Sen. Jim DeMint, the South Carolina Republican and ideological leader of conservatives who identify with the Tea Party on Capitol Hill, is leaving the U.S. Senate to head an influential conservative think tank.
DeMint will leave the Senate in January to be president of The Heritage Foundation, according to a statement released today by his office.
"I'm leaving the Senate now, but I'm not leaving the fight," DeMint said in the statement. "I've decided to join The Heritage Foundation at a time when the conservative movement needs strong leadership in the battle of ideas. No organization is better equipped to lead this fight and I believe my experience in public office as well as in the private sector as a business owner will help Heritage become even more effective in the years to come. "
DeMint served three terms in the House of Representatives before coming to the U.S. Senate in January of 2005. He was reelected in 2010. His influence has grown in the Senate, particularly among conservatives, because he has been an often uncompromising advocate for much smaller government.
In a party that has been mobilized against the White House since President Obama took office, DeMint has been particularly outspoken.
He has been a vehement opponent of the Obama administration on everything from the 2009 stimulus to the president's health reform law. DeMint called the president a "bully" for trying to pressure the Supreme Court on Obamacare.
But DeMint's legacy may be less important for his opposition to the Obama administration than for the effect he had on his own party, drawing it further to the right.
His departure from the Senate means the Tea Party movement, which saw setbacks in the 2012 election season, will be without it's top elected voice.
"Jim helped provide a powerful voice for conservative ideals in a town where those principles are too often hidden beneath business as usual," said Senate Minority Leader Mitch McConnell. "There is no question in my mind that he raised the profile of important issues like spending and debt and helped galvanize the American people against a big government agenda. I am confident that he will continue to advocate for conservative principles in the next chapter of his service to the American people."
DeMint has often found himself at odds with McConnell and other party elders. DeMint, for instance, tried in 2010 to force Republicans to give up the practice of earmarking federal dollars for home state projects. He failed to gain enough support in the party, but did make government waste a key political issue.
Sen. Lindsey Graham, the other South Carolina Republican senator, who has had a more troubled times with the party base, said Friday on the Senate floor that he liked playing "good cop, bad cop" with DeMint at times in Senate fights.
It is not clear which conservative will step into DeMint's shoes.
"My constituents know that being a senator was never going to be my career," DeMint said. "I came to Congress as a citizen legislator and I've always been determined to leave it as citizen legislator. South Carolina has a deep bench of conservative leaders and I know Governor Haley will select a great replacement."
Not satisfied with moderates in the Republican Party, he has led efforts to recruit and fund more conservative alternatives. He was particularly active in the 2010 midterm, helping Marco Rubio defeat then-Republican and then-moderate Charlie Crist in Florida. DeMint also helped Republican Christine O'Donnell defeat Rep. Mike Castle in the Delaware Republican primary.
But those two races show the mixed success DeMint's strategy can bring. Rubio has become a rising star in the Senate and for conservatives. But O'Donnell lost her bid in the general election and Republicans lost the opportunity to gain that seat in the senate.
Rubio offered a video message after learning that DeMint was leaving the senate. "Jim DeMint is one of the main reasons I'm in the U.S. Senate," said Rubio, who added he is excited that DeMint will continue to "lead the limited government free enterprise movement from outside the Capitol."
"One of the most rewarding things I've done in the Senate is work with the grassroots to help elect a new generation of leaders who have the courage to fight for the principles of freedom that make this country so great," DeMint said. "I'm confident these senators will continue the legacy of conservative leaders before them."
That's a legacy that even Graham, who could well face a primary from a more conservative republican in 2014, can agree with.
"What he's done over the last four years to build a conservative movement, to get people involved in politics, like Marco Rubio, who Jim helped early on in his primary I just think is going to be a great legacy," said Graham.
Before Congress, DeMint owned an advertising and market research firm. Gov. Nikki Haley, a Republican, will appoint a replacement for DeMint until the next regular statewide election.
Regarding Haley's appointment of a replacement for DeMint, one knowledgeable South Carolina Republican source points to Congressman Tim Scott, who represents the state's 1st Congressional district.
"Tim Scott is the undisputed favorite -- and probably preferred by Jim DeMint," said the South Carolina Republican. "It would be historic for an Indian American governor from the Deep South to appoint an African American to the U.S. Senate. I think it's highly unlikely she would appoint a placeholder. There are too many critical votes coming in the next 24 months. Scott and DeMint are lock step on the issues."
Scott thanks DeMint for his service in his own statement Thursday.
"Looking forward, Governor Haley will now appoint a new Senator, and I know she will make the right choice both for South Carolina and the nation," he said.
The other option for Haley is to appoint someone who does not have aspirations on higher office - a placeholder who would step aside for the special election, allowing Haley and others an opportunity to pursue the seat.