Nov. 5, 2013 -- intro: Charlie Crist announced Monday that he would run again for his old job as governor of Florida, with one major difference: He's running as a Democrat.
Republican Crist served as Florida's governor from 2007 to 2011. The charismatic former governor was a star in the GOP during his tenure. He cited Ronald Reagan as his role model, and was even considered to be John McCain's running mate in 2008.
But when he decided to run for an open U.S. Senate seat in 2010, he was challenged on the right by then-Speaker of the Florida House of Representatives Marco Rubio. This prompted Crist to run as an independent, which did not fare well for him, and he eventually lost the race.
Crist, 57, has since become increasingly moderate and even endorsed President Obama's 2012 re-election bid. Then, in December 2012, the former governor made his party switch official, and registered as a member of the Democratic Party.
Crist, however, is not the first notable politician to effectively switch political parties during the course of his or her career. ABC News has compiled a list of 21 famous figures who jumped ship to become members of political parties they once opposed.
quicklist: 1 title: Ronald Reagan text: Although he is the one president who is near universally revered among Republicans, Ronald Reagan used to be a Democrat before he changed his party affiliation to Republican in 1962.
Reagan, who was president of the Screen Actors Guild before being elected governor of California in 1966, was fiercely anti-Communist. He supported presidential candidates who shared this view, such as Dwight Eisenhower and Richard Nixon. Reagan even challenged incumbent President Gerald Ford in the 1976 Republican primary. Though he lost that race, he eventually beat President Jimmy Carter in the 1980 presidential election.
As president, Reagan supported other conservative policies like limited government and lower taxes. Despite this, some of Reagan's previously held Democratic beliefs, such as ridding the world of nuclear weapons, stayed with him throughout his presidency, which he held for two terms from 1981 to 1989.
When he did formally switched parties, Regan said he never really left the Democratic Party, but rather, the Democratic Party left him. media: 16580953
quicklist: 2 title: Hillary Clinton text: As a teenager, she volunteered and campaigned for Republican Richard Nixon's presidential campaign, worked for Republican Barry Goldwater's campaign in 1964 and was even elected president of Wellesley College's Young Republicans Club.
That's right, Hillary Clinton was once a member of the GOP.
But in the early 1970s, Clinton left the Republican Party and has never looked back. Clinton decided to leave the Republican Party because of policy issues like the Vietnam War, and began to help campaign for candidates like Eugene McCarthy.
Clinton, a beloved member of the Democratic Party, has arguably the most impressive political resume of any party member. She has held the position of first lady, U.S. senator from New York, primary candidate for the 2008 Democratic presidential nomination and, most recently, secretary of state.
Clinton took a much needed break from politics after finishing her term as secretary of state, and has recently returned to the political stage, bringing back much support and speculation of a 2016 run. media: 19913960
quicklist: 3 title: Theodore Roosevelt text: Teddy Roosevelt's call for a new political party came after he left the White House. His former secretary of war, William Taft, had secured the presidency in 1908 with Roosevelt's recommendation, but tension developed between the two as Taft's politics became more conservative.
Roosevelt decided to seek the presidency again in 1912, but he was sidelined by incumbent Taft's control of the Republican Party. So Roosevelt and his supporters started their own party, called the Progressive Party, or the "Bull Moose Party."
Although Roosevelt lost the election to Woodrow Wilson, with 88 electoral votes, he became the only third-party presidential candidate to best an established party's candidate (William Taft, who received 8 electoral votes).
Roosevelt was also the only 1912 presidential candidate to endorse national women's suffrage. media:
quicklist: 4 title: Donald Trump text: In a potential attempt to find a way into the 2012 presidential race, real estate mogul and reality-television star Donald Trump switched his party affiliation from "Republican" to "unaffiliated" in December 2011.
"If the Republicans pick the wrong person I would, in fact, seriously consider running," Trump said at the time of his choice in a Web video.
Trump had become dissatisfied with the Republican Party's handling of certain issues, particularly a then-recent payroll tax cut deal.
Just after the switch, Trump's top political adviser, Michael Cohen, told ABC News, "One thing is for certain, Donald Trump is adamant that Barack Obama must be defeated in 2012 under any circumstances." media: 15478537
quicklist: 5 title: Pat Buchanan text: Conservative commentator Pat Buchanan has not always been loyal to the GOP. After serving under presidents Nixon, Ford and Reagan, and losing the Republican presidential nomination in 1992 and 1996, Buchanan sought the presidency under the Reform Party, founded by Ross Perot, in 2000.
The bid was unsuccessful and marred by the Florida recount controversy. Buchanan received only 0.4 percent of the popular vote. In the years after the election, he separated himself from the Reform Party and identified himself as an independent.
Prior to the 2004 presidential election, Buchanan announced that he had returned to the Republican Party and gave a half-hearted endorsement for George W. Bush's re-election.
"While I disagree with the president on trade policy, Iraq, immigration policy and big government, I agree with him on taxes and judges and values and sovereignty," Buchanan said. "I disagree with Kerry on everything." media: 20791393
quicklist: 6 title: Leon Panetta text: A native Californian, Leon Panetta began his political career as a legislative assistant for Sen. Thomas Kuchel, a liberal Republican, in 1966. After spending a few years working on the Hill, Panetta joined the Nixon administration as director of the Office of Civil Rights. He then left the administration after serving one year, and switched party affiliations.
As a new member of the Democratic Party, Panetta worked as New York City Mayor John Lindsay's executive assistant for just a year, before returning to California. In 1976, Panetta began his own career on the Hill, as a Democratic House member from California. Panetta was re-elected to the House eight times, and rose up the ranks to chair the House Budget Committee.
Panetta moved from the Hill to the executive branch in 1992, as President Bill Clinton's choice to head the Office of Budget and Management, and just two years later, Panetta moved into the White House as Bill Clinton's chief of staff. In 2009, Panetta was called on by the White House again, this time by President Obama to direct the CIA. media: 18213962
quicklist: 7 title: Lincoln Chafee text: Lincoln Chafee began his career in Washington by stepping in to fill his father's Senate seat in 1999. The son of the moderate Republican then went on to be elected to a full term, as a Republican in 2000.
Chafee spent his full term in the Senate in strict opposition to Republican President Bush, standing up against many of the former president's policy decisions, including being the only GOP senator to refuse a resolution authorizing the United States to attack Iraq.
After leaving the Senate, Chafee formally left the Republican Party in 2007, in favor of an independent affiliation, and won the Rhode Island governorship in 2010 in a competitive three-way race.
Chafee shares a close friendship with the highest ranking member of the Democratic Party, President Obama, from their time spent working together in the Senate. When considering a re-election run in 2013, Chafee decided to make another party switch, and joined his friend's party.
Obama welcomed Chafee to the Democratic Party with open arms in May but, ultimately, the governor decided not to seek a second term, and opted out of Rhode Island's gubernatorial race. media:
quicklist: 8 title: Condoleezza Rice text: Condoleezza Rice has served as President George W. Bush's secretary of state and national security advisor, but she was a registered Democrat until 1982, casting her vote for Jimmy Carter in 1976.
But it was Carter who swayed Rice, then a 28-year-old assistant political science professor at Stanford, to the Republicans' side, dismayed as she was by his decision to invade Afghanistan in 1979. Rice registered as a Republican and cast her vote for Ronald Reagan in 1982.
At the Republican National Convention in 2000, she revealed that her father, "the Republican I admire most," also inspired her decision to switch, saying "My father joined our party because the Democrats in Jim Crow Alabama of 1952 would not register him to vote. The Republicans did."
Rice went on to say that she had found a party "that sees me as an individual, that puts family first, that believes that peace begins with strength." media: 20790867
quicklist: 9 title: Rick Perry text: Unlike Rice, Texas Gov. Rick Perry flipped away from his father's political party affiliation. But the one-time Republican presidential candidate hopeful had quite the blue history before switching tracks.
Perry began his political career in 1984, when he was elected as a Democrat to the Texas House of Representatives. He then went on to support Al Gore in the 1988 Democratic presidential primaries, serving as the campaign chairman for the state of Texas.
It was the 1988 presidential primary election that inspired Perry's party switch, he later told the Austin-American Statesman. He put a check by George H. W. Bush's name instead of the Democrat Michael Dukakis and said he "came to my senses."
The switch came right before Perry's successful campaign for the state's agriculture commissioner position.
Asked at a Dallas builders meeting how he and one-time compatriot Gore could have gone down such divergent paths ("Did you get religion? Did he get religion? What has happened since then?"), Perry responded "I certainly got religion, I think he's gone to hell." media: 20686771
quicklist: 10 title: Norm Coleman text: Former Minnesota Sen. Norm Coleman was once a flower child, anti-Vietnam protesting liberal before switching to the Republican Party.
Though Coleman would later make headlines in a heated 2008 election that resulted in a six-month legal battle and eventual lost of the incumbent seat to Democrat Al Franken, he started his political career on the same side.
Coleman was elected mayor of St. Paul, Minn., as a member of the Democratic-Farmer-Labor Party, where he was widely popular for helping bringing a professional hockey team back to the state.
But the onetime counterculture roadie and Woodstock attendee was unpopular with more liberal Democrats, even as the co-chair of Bill Clinton's presidential campaign in Minnesota. He made the switch to the Republican Party in 1996 and was re-elected as mayor that year, despite his new affiliation. media: 20791217
quicklist: 11 title: Strom Thurmond text: The longtime South Carolina senator and South Carolina governor was a Democrat for quite some time, alas not one resembling a present-day Democrat.
Thurmond was more representative of a typical Dixiecrat. The Dixiecrats were a short-lived political party that broke away from the Democratic Party in 1948 in light of its support for segregationist and Jim Crow-era policies.
Thurmond was a big opponent of desegregation and decamped to the Republican Party in 1964. This was due in no small part to his opposition of the Civil Rights Act of 1964 and his support for one of its biggest opponents, ultra-conservative Arizona Senator Barry Goldwater in his run for the presidency. media: 18674174
quicklist: 12 title: Susana Martinez text: Republican Susana Martinez has one of the highest governor approval ratings in the country, and that includes more than 44 percent of Democrats in New Mexico. So maybe it should come as little surprise that Martinez was once one herself.
The first female Hispanic governor in the United States, Martinez was a Democrat until 1995. She shared the story of her switch at the 2012 Republican National Convention in a speech preceding Paul Ryan's.
Before running for district attorney of Las Cruces, N.M., in 1996, a Republican friend took Martinez and her husband to lunch to talk about political issues. That meal led to a change of heart.
"When we left that lunch, we got in the car and I looked over at Chuck and said, 'I'll be damned, we're Republicans.'" media:
quicklist: 13 title: Michael Bloomberg text: Perhaps it is Michael Bloomberg, outgoing mayor of New York, who has flip-flopped the most. A lifelong Democrat, Bloomberg switched colors in 2001 and ran for mayor as a Republican, winning a second term in 2005 with the same affiliation.
But his past was ever present in his policies, as the billionaire CEO mayor supported abortion rights, same-sex marriage, gun control and stem cell research throughout his term.
Prior to campaigning to change New York's term limit laws, claiming his expertise would be needed during the impending Wall Street financial crisis, and winning a third term in 2009, Bloomberg switched again -- this time as an independent -- in 2007. The move was largely, and incorrectly, predicted as a foreshadow for a potential independent presidential campaign in 2008.
In an official statement, Bloomberg said leaving the Republican Party "brings my affiliation into alignment with how I have led and will continue to lead our city. As a political independent, I will continue to work with those in all political parties to find common ground, to put partisanship aside and to achieve real solutions to the challenges we face." media: 20120160
quicklist: 14 title: Arlen Specter text: Arlen Specter served as a Republican senator from Pennsylvania from 1981 to 2009 and as a Democrat from 2009 to 2011.
Specter actually served two stints as a Democrat and one as a Republican during his professional career. In 1965, Specter lost the Democratic nomination for Philadelphia district attorney and switched his affiliation so he could still run for the position, though this time as a Republican.
Though he remained a Republican until 2009, he was always considered a moderate and was one of six Republican senators to vote against Robert Bork's Supreme Court nomination in the 1987. Perhaps the last straw among fellow Republicans was Specter's vote for President Obama's 2009 stimulus bill.
As Specter found himself being alienated by some of his colleagues, he switched parties and said: "I now find my political philosophy more in line with Democrats than Republicans." media:
quicklist: 15 title: Elizabeth Warren text: Sen. Elizabeth Warren is best known as a liberal favorite and Democratic senator from Massachusetts, but before serving in Congress as a Democratic senator, Warren admitted she was once a Republican.
In a 2011 interview with the Daily Beast, Warren said, "I was a Republican because I thought that those were the people who best supported markets. I think that is not true anymore." She continued, "I was a Republican at a time when I felt like there was a problem that the markets were under a lot more strain. It worried me whether or not the government played too activist a role."
Warren has held many roles in the Democratic Party, notably working as an assistant to President Obama and helping to design the Consumer Financial Protection Bureau, before her work as a senator on Capitol Hill. media: 17690201
quicklist: 16 title: Joe Lieberman text: Former Sen. Joe Lieberman started his political career in Congress as a freshman Democratic senator in 1988. Lieberman continued to rise through the ranks of the party serving in the Senate for three consecutive terms, and in 2000, the senator from Connecticut was selected to join the Democratic Party's presidential campaign.
But after the Democratic Party lost the 2000 presidential election to George W. Bush, Lieberman found himself on the road to a slow separation from his party and, in 2006, ran for re-election to the Senate as an independent.
After spending his political career batting for the Democratic Party, the former vice presidential candidate found himself swinging for another team, as a star speaker at John McCain's Republican convention.
In the end, Lieberman told the Daily Beast's Howard Kurtz, "I feel the Democratic Party left me. It was no longer the party it was when I joined it in the image of President Kennedy." media: 20791012
quicklist: 17 title: Jesse Helms text:Jesse Helms served as a U.S. Senator from North Carolina from 1973 to 2003, including six years as chairman of the Senate Committee on Agriculture, Nutrition and Forestry.
Helms was a senator much in the mold of fellow Sen. Strom Thurmond. Helms switched his party affiliation to Republican in 1970 after experiencing frustration with Democrats pro-civil rights policy stances. Indeed, Helms even led a 16-day filibuster in the 1980s to protest the Senate's decision to make Martin Luther King Jr. Day a federal holiday.
Helms was very controversial during his Senate career, especially in terms of civil rights. In addition to the King Day filibuster, Helms also opposed President Clinton's nomination of Roberta Achtenberg to be assistant secretary of Housing and Urban Development because he thought her to be a "militant-activist-mean lesbian." Helms was also criticized for an ad released during his 1990 re-election in which he accused his opponent Harvey Gantt, an African American, of supporting racial quotas. media:
quicklist: 18 title: Arianna Huffington text:Now the president and editor in chief of the progressive-leaning website The Huffington Post, Arianna Huffington was once a conservative commentator in the mid-1990s.
She supported Republican presidential candidate Bob Dole in the 1996 election and appeared as the right-wing counterpart to the liberal comedian and now-Sen. Al Franken in Comedy Central's "Strange Bedfellows" during the election.
Her allegiance started to shift in the late-90s. In 1998, she told The New Yorker's Margaret Talbot, "the right-left divisions are so outdated now. For me, the primary division is between people who are aware of what I call 'the two nations' (rich and poor), and those who are not."
She launched an unsuccessful bid for governor of California in 2003 as an independent and endorsed John Kerry for president in 2004. When announcing her endorsement on Jon Stewart's The Daily Show, Huffington said, "When your house is burning down, you don't worry about the remodeling." media: 19308110
quicklist: 19 title: Trent Lott text: Trent Lott was a U.S. senator from Mississippi from 1989 to 2007 and spent many of those years in leadership positions such as Senate majority and minority whip, as well as Senate majority and minority Leader.
Lott was a longtime Democrat, but became a Republican in 1972. Lott had previously worked in the office of Democrat Rep. William Colmer, also of Mississippi. Colmer himself became more conservative during his time in Congress and eventually turned against policies like public housing, welfare and civil rights. Lott's views changed in tandem with that of his boss, whose House seat he ran for as a Republican after Colmer's retirement.
Lott stepped down as Senate majority leader in 2003 and was succeeded by Sen. Bill Frist, R-Tenn., after he made some controversial comments at Strom Thurmond's 100th birthday party in favor of Thurmond's 1948 presidential run.
quicklist: 20 title:Teresa Heinz Kerry text: Teresa Heinz Kerry, wife of Secretary of State John Kerry, reportedly left the Republican Party for the Democratic Party out of "disgust" in 2002. She cited Republican attack ads on Sen. Max Cleland, D-Ga., a wounded veteran, during his 2002 re-election campaign for her disgust.
"Three limbs, and all I could think was, 'What does the Republican Party need, a fourth limb to make a person a hero?'" Heinz Kerry said in a 2004 interview with CBS.
Her switch to the Democratic Party came in the same year that her husband launched his ultimately unsuccessful run for president in the 2004 election. media: 19601975
quicklist: 21 title: Elizabeth Dole text: Elizabeth Dole served as a U.S. Senator from North Carolina from 2003 to 2009. Dole worked for President Lyndon Johnson in the White House Office of Consumer Affairs and stayed there once Richard Nixon was elected.
Dole switched her party affiliation in 1969 to Independent, when Nixon appointed her as director of the President's Committee for Consumer Interests. Then a Federal Trade Commissioner, Dole became a Republican in 1975 around the same time she married future Sen. Majority Leader Bob Dole.
Dole also served in the Reagan administration as secretary of transportation from 1983 to 1987 and as secretary of labor from 1989 to 1990.
Dole lost her 2008 re-election bid to then-North Carolina State Sen. Kay Hagan.