If Republicans had won big on November 6, it’s likely Jim DeMint would not be leaving the Senate to head the Heritage Foundation. In a conversation not long after the announcement, DeMint expressed frustration with being a “Doctor No” in the Senate, that is, a minority lawmaker who spends his time usefully but unhappily stopping misguided legislation. He also expressed a strong desire to become the kind of powerful force in the political world that is not possible for a Republican senator right now. In a move that stunned many Washington insiders, DeMint decided the path to more influence was to leave elected office.

“Yes, I’m frustrated,” he told me. “If Romney was in the White House and Republicans had control of the Senate, I would have had a chance to advance positive ideas, so there would have been a very different scenario.”  But that’s just not the case.  DeMint explained that he believes “it’s an important role in the Senate to be here and try to stop bad legislation when you’re in the minority,” but the election results made clear that conservatives face more urgent problems.

DeMint said many people were shocked that a U.S. senator would give up his seat.  But given today’s political situation, he believes he will have greater influence — not just on the public debate generally but specifically on the Senate — from the outside.  “I won’t be taking votes, but I guarantee you I will affect more votes at the Heritage Foundation than I do in the Senate.”

DeMint’s move is an enormous break with tradition in his native South Carolina.  Predecessors Strom Thurmond and Ernest Hollings served a total of 85 years in the Senate and retired at ages 100 and 83, respectively.  DeMint is 61 and has served in the Senate just since January 2005.  He is leaving two years into a six-year term; certainly some South Carolinians who voted for him are unhappy about that. “People in South Carolina knew I wasn’t going to make this a career,” DeMint told me.  “A lot of them didn’t like it when I said I was going to leave the House after six years, and I announced after the last election that I wasn’t going to run again.  I would not leave the Senate unless I thought I could serve South Carolina better at the Heritage Foundation.”

That’s the frustration again.  Facing defeat after defeat in a situation in which the most he could do was stop some bad things from happening, DeMint didn’t see much conservative vigor among his colleagues.  “I just believed that Republicans have not been reliable partners of the conservative cause,” he said. “I think there is a lack of vision and boldness that we need at the national level.  I’m not pointing to anyone in particular, but it’s been a long time since I’ve been in a conservative conference where someone stood up and just inspired people with a message of what we really stand for and what America needs at this point.”

The result of that continuing Republican weakness has been — no surprise — Democratic victories.  The 2012 results convinced DeMint that those victories weren’t flukes and might go on for quite a while if Republicans don’t change. “After the election it was clear that a majority of Americans believe the Democratic Party can do more for them than Republicans,” DeMint said.  “Yet I know, factually, provably, that conservative ideas are working at the state level all around the country.  Right-to-work states are attracting businesses.  School choice is working for minorities and the poor.  And we can prove that Obama’s policies, liberal, progressive policies, in California, Illinois, New York — you can see where they’re going.  We are going to continue to lose elections at the national level if we don’t convince Americans that our ideas are better.”

Frustration aside, there’s been talk that DeMint, not particularly wealthy by Senate standards, is cashing out by going to Heritage.  He’ll certainly do well; the outgoing president, Ed Feulner, earned more than $1 million a year.  But as The Washington Examiner’s Tim Carney pointed out, DeMint actually chose not to go for a big-money lobbying payout. “DeMint, who in the Senate was a leading opponent of cronyism and corporate welfare, didn’t go the corporate cashout angle,” Carney wrote.  “He is taking a slightly smaller payday then he could otherwise (a two-term senator who sat on Commerce could pocket about $1 million for a job where he didn’t do anything, and he could get very rich at a job where he actually worked).”

Obviously the timing of Feulner’s departure influenced DeMint’s choice.  But DeMint also explained that a major factor in his decision was his concern that the country is going downhill fast.  “If I thought I could wait four years and do this — I just don’t think there’s time,” he said.  “If there was time, I’d hang in there, be ranking member on Commerce for four years, and get a job making a few million a year at a wireless association or something.  But that’s not what it’s about for me.”