From the unexpected Senate election in Massachusetts to the emergence of a conservative Tea Party movement that proved to be a force to be reckoned with during a contentious election season to a roller-coaster of victories, defeats for the White House, 2010 has been a head-spinning year for political news.
ABC News has compiled some of the highlights, which not only made headlines over the past year, but that are also likely to affect the shape of things to come in 2011.
Scott Brown Shocker
Some dubbed it the "Massachusetts Miracle" or the "Scott heard 'round the world." Whatever you call it, Republican Scott Brown's victory in the special election held to replace the late Sen. Edward M. Kennedy stunned the political world.
In an overwhelmingly Democratic state, the GOP state senator defeated the state's Democratic Attorney General Martha Coakley, who had been the heavy favorite to win until just weeks before the election. In the end, Brown was able to put together a coalition of Republican and independent voters to capture 52 percent of the vote compared with Coakley's 47 percent.
Not only did Brown scoop up a Senate seat held by Kennedy for nearly half a century, he also ended the Democrats' filibuster-proof super majority in the chamber, complicating the party's plans for passing health care reform, an issue that Kennedy said was "the cause of my life."
Many Democrats also worried that Brown's election would be a preview of things to come 10 months later in the November midterm elections -- a prediction that turned out to be correct.
Health Care Overhaul Passes
It took more than a year of debate and negotiation, but in March, the Obama administration's most important domestic priority -- health care overhaul -- got the green light from Congress, followed by the president's signature. Democrats celebrated the bill as an achievement on par with Social Security and Civil Rights legislation.
"This is what change looks like," President Obama declared. "We proved that we are still a people capable of doing big things."
The vote also appeared to be a big win for House Speaker Nancy Pelosi.
But during a heated debate on the House floor, Minority Leader John Boehner delivered a stem-winder of a speech lashing out at Democrats.
"Can you say it was done openly, with transparency and accountability -- without backroom deals, struck behind closed doors, hidden from the people?" the Ohio Republican asked. "Hell no, you can't!"
Boehner and other Republicans vowed to make the passage of the health bill one of their biggest rallying points heading into the midterm elections.
Tea Party Rallies
By the end of primary season this year, it was clear the Tea Party had emerged as a full-fledged political force.
Insurgent conservative candidates, with the backing of one or more loosely-affiliated Tea Party groups, scored a string of big wins in key races, taking down GOP Sen. Bob Bennett of Utah, Rep. Mike Castle of Delaware, Gov. Charlie Crist in Florida, Sue Lowden in Nevada and establishment candidate Trey Grayson in Kentucky.
In their places, Mike Lee, Christine O'Donnell, Marco Rubio, Sharron Angle and Rand Paul went on to challenge Democratic and independent opponents in their state's general elections -- with varying degrees of success.
It's a signature aspect of the Tea Party that followers have been willing to take on Republicans as well as Democrats.
They also know how to turn out a crowd. Gatherings across the country this year, including a mega-rally in Washington featuring Fox News host Glenn Beck and Sarah Palin, drew thousands.
Though the Tea Party remains amorphous and its power in the legislative arena is largely untested, devotees will comprise a significant share of the incoming members of the House and Senate.
Economic Woes Continue
2010 continued to be a difficult year for struggling businesses, for the pocketbooks of average Americans and for more than 9 percent of Americans who are unemployed.
Uncertainty persisted across the country and voters registered their unease in November. According to national exit polls, more than two-thirds of Americans said the country was headed seriously off on the wrong track, while only 14 percent said their own family's financial situation had improved in the last two years compared to 41 percent who said they were worse off.
While the seeds of recovery appear to be taking root, it's been a slow process that has frustrated politicians from both parties, but none more so than Obama, who will ultimately bear the lion's share of responsibility for how Americans feel about their economic well being.
Witches and Demon Sheep Appear
Who would have thought that the release of a Web ad featuring a fake sheep with laser-red eyes and a Delaware Senate candidate's defense of her past statements about dabbling in witchcraft would be among the most enduring moments of the 2010 campaign. But this was no ordinary political year, and it was certainly one of the strangest for political ads.
The so-called "Demon Sheep" ad helped boost the primary campaign of California Senate candidate Carly Fiorina. The ad used a wolf-in-sheep's-clothing theme to portray Fiorina opponent Tom Campbell as a "fiscal conservative in name only."
Fiorina won her primary, but ended up losing the general election to incumbent Sen. Barbara Boxer.
Across the country in Delaware a little-known Senate contender, Christine O'Donnell, was making big waves not only with her campaign but with a remarkable ad in which she declared: "I am not a witch. I'm nothing you've heard. I'm you."
O'Donnell was responding to a previous acknowledgement of her experience with the dark arts. The ad came to define her campaign, which she ended up losing to Democrat Chris Coons.
Pelosi Gets Vilified
The midterm elections were not kind to House Speaker Nancy Pelosi, who found herself the target of attack ads, not only by Republicans, but also by some vulnerable members of her own party.
"Is our congressman a lap dog?" asked the narrator of an ad produced by the National Republican Congressional Committee in Kentucky. "Ben Chandler's not listening to Kentucky, but Chandler is listening to Nancy Pelosi. Ben Chandler votes with Pelosi's leadership 94 percent of the time."
"Isn't one Nancy Pelosi enough?" declared another NRCC ad hitting New Hampshire congressional candidate Annie Kuster.
Pelosi emerged as a convenient and effective target and it turns out that more money was spent on commercials that included attacks on her than against any other congressional leader since Newt Gingrich, according to the Campaign Media Analysis Group, which tracks ad spending.
Democrats Get Shellacked
Even if they didn't want to admit it until after Election Day, the writing seemed to be on the wall for Democrats in November. They suffered painful defeats in House, Senate and governors races and in state house contests throughout the country.
For the first time in four years, the GOP re-captured the House of Representatives, cruising to a new majority by winning some seats held by relatively new Democratic members as well as ousting long-time incumbents. Republicans also did well in Senate races, expanding their power base in the upper chamber, but falling short of a majority.
"People are frustrated," Obama said at a press conference after the November elections, describing his party's losses as a "shellacking." He continued, "They're deeply frustrated with the pace of our economic recovery."
The president also used the electoral rebuke as a moment of personal reflection, conceding that in his job it was too easy to "lose track of ... the ways that we connected with folks that got us here in the first place."
It was a profound victory for Republicans who quickly named a new House Speaker -- Ohio's John Boehner.
Sarah Palin's America
It seemed like Sarah Palin was the super nova of the political world this year, drawing just about everything and everybody into her orbit.
Through her political action committee, SarahPAC, which raised millions this year, her Facebook and Twitter pages, her public speeches, candidate endorsements and television appearances, Palin managed to insert herself into the thick of the electoral politics and command more media attention than perhaps any other Republican political figure.
And she was just as active in the realm of popular culture. She released a new book, "American By Heart," starred in her own reality television show "Sarah Palin's Alaska," and cheered on her daughter, Bristol, a contestant this year on "Dancing With the Stars."
Palin spent time trying to establish her policy credentials in a series of op-eds and missives on Facebook and she made news when she responded to a question from ABC's Barbara Walters who asked whether she thought she could beat President Obama in 2012.
"I believe so," Palin said in the interview, dropping yet another clue about her potential political ambitions.
Lame Duck Wasn't So Lame
With the midterm elections in the rearview mirror and the year drawing to a close, Congress was left with a raft of unfinished business. Lame duck sessions usually produce very little in the way of real legislation, but as we soon found out, this was no ordinary lame duck.
More major bills got passed during the month of December than in much of the rest of the year.
Accomplishments included a tax cut compromise negotiated by the White House and Congressional Republicans, the repeal of the military's "don't ask, don't tell" policy, ratification of the START arms reduction treaty with Russia and the passage of a bill to help 9/11 first responders.
Veteran Congressional observers called it the most produce lame duck session in history.
But not everybody was happy with all the legislative progress.
"I am not proud of this process. I'm not proud of this lame duck," said Sen. Lindsey Graham, R-S.C., who complained that Democrats steamrolled Republicans in the closing days of the session.
He and other Republicans pointed the finger at Senate Majority Leader Harry Reid, who charged ahead with his party's agenda knowing that a stronger Republican contingent in the Senate and a GOP majority in the House were just weeks away.
Here's Looking At You, 2011
As wild a ride as 2010 was, there are likely even more surprises in store in the coming year. We already know that there is change in store at the White House.
Senior adviser David Axelrod is expected to leave early in the year as he turns his attention to the president's re-election effort. New faces will be popping up in the West Wing and no one knows just how significant a staff shakeup the president has planned.
It will be a brand new era on Capitol Hill, with soon-to-be House Speaker John Boehner at the helm. How much will he be willing to work with Democrats and is there any hope for bipartisanship in either chamber?
And what does the future hold for Nancy Pelosi who, instead of fading from the spotlight after the Democrats' stinging defeat at the ballot box, ran for and won the position of House Minority Leader?
Also worth keeping an eye on are the politicians who swept into power under a Tea Party mantle. Will they stick to their principles or follow in the footsteps of Scott Brown, who has lately emerged as a Senate GOP ally of the Obama administration on a variety of issues, including the repeal of "don't ask, don't tell" and ratification of the START agreement.
Those votes earned him the ire of some members of the Tea Party, who backed his Senate campaign, but are now talking about recruiting a candidate to his right to take him on in a primary in 2012. How quickly things change.
And perhaps the biggest elephant in the room is the nascent 2012 presidential contest.
Some potential Republicans candidates are already traveling the country, buttering up donors and laying the groundwork to mount campaigns. None have officially entered the race, and the primary dynamics are as strange as they've ever been with several possible GOP contenders keeping a close eye on Sarah Palin's next move before they decide on theirs.
Who gets in, who stays out and who's got the best chance to beat Obama?
Lots of questions and the answers are right around the corner: 2011, here we come.