During slow moments in the United States Senate—and there are many, many of them in the world’s most deliberative body—staffers like to play a little game called “mapping.” In it, they take a look out on the graybeards occupying the seats on the Senate floor and sketch out what would happen if one of them were to retire or decide to run for another office. Who will vie for the open seat? What will happen to the committee slots the outgoing senator holds?

But few maps would have included the lightning bolt that struck the Capitol on Thursday, when Tea Party firebrand Jim DeMint announced, “I’m leaving the Senate. But I am not leaving the fight.” In taking up a new post as head of the Heritage Foundation, DeMint pulled off a move many lawmakers would have considered laughable: leaving elected office—for a think tank no less!—because the gig isn’t powerful enough.

But conversations with several Senate staffers and Capitol Hill insiders say the shock is unmerited.

“He really hates the Senate,” said one D.C.-based conservative political operative. “And who wouldn’t? This place is terrible for a conservative—you have both sides arguing about how to slow the growth of government, not how to make government smaller. DeMint has left his legacy.”

DeMint’s tenure in the Senate will be remembered for two things: for him being a one-man stopper of legislation that a large chunk of the body approved, thus making the ultra-slow Senate even more dysfunctional; and for frustrating Republican leadership by running conservative challengers against the establishment’s preferred choice—and often winning.

It was DeMint, after all, who endorsed Rand Paul the day after Senate Minority Leader Mitch McConnell endorsed Paul’s opponent (in McConnell’s home state, no less!); who was an early backer of Ted Cruz in Texas, even though seemingly the entire political universe favored a more mainstream conservative candidate; and who early on got behind Tea Party-backed candidates like Jeff Flake of Arizona and Mike Lee of Utah. The problem with this approach, however, was that it backfired almost as often as it worked—witness his lonely support of Todd Akin in Missouri, his unheard-of encouragement of Richard Mourdock to challenge sitting Sen. Richard Lugar, and his support of Sharron Angle in Nevada. Had DeMint held his fire on any of these, the GOP would have been that much closer today to regaining the majority.

Thus it was with gritted teeth, one could imagine, that McConnell praised DeMint in a statement for his “uncompromising service” (an understatement to say the least.)

“Jim helped provide a powerful voice for conservative ideals in a town where those principles are too often hidden beneath business as usual. 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” McConnell said.

Senate insiders though, say DeMint never much had the stomach for the minutiae of lawmaking, that despite his apparent fondness for procedures that bottled up legislation, he was more comfortable taking up the flag for a crusade.

“He isn’t someone who liked being in the middle of politics of issues,” said one staffer who worked closely with DeMint. “I don’t think he liked the nuance of administering over legislation.”

Opinion on the Hill is divided about whether the Senate will run more smoothly with DeMint gone. On the one hand, he has created a legion of followers in his wake—Cruz, Marco Rubio, and the like. But on the other, no one has quite proven so willing to draw a thick line in the sand quite like DeMint.

“The beauty of the Senate is that one senator can stop anything, but you have to really have some backbone to do it,” said one former top Republican staffer. “There is a lot of pressure on you. You have to keep the Senate in session, and you have members calling you up, telling you, ‘C’mon it’s my youngest daughter’s graduation from college this week;’ stuff like that. And he would do it anyway.”

There is an opening, then, for a Republican who wants to take on that role. It is unlikely to fall on DeMint acolytes like Rubio or Paul, relative youngsters with ambitions of even higher office, but GOPers say they expect Lee or perhaps Pennsylvania’s Pat Toomey to now take on a greater role in the chamber.

DeMint’s move also provides a big opening for John Thune. DeMint was slated to be the ranking member of the Commerce committee after the retirement this year of Kay Bailey Hutchison, but with him gone, that job will fall to the senator from South Dakota. It is one of the plum spots in the body, the one with oversight of most of the nation’s economic activity. Thune has been mentioned as a possible presidential contender in 2016, and this promotion seems sure to prove that his campaign coffers are filled.

For DeMint however, there seems to be little doubt about what the future will bring. Free of the rigors of actually making laws, and without the strictures of the Senate—as much as he bucked them—he will be free to try and remake the Senate and the world into the more conservative place he thinks they should be.

“Jim DeMint will maintain his influence, but he will be that much more difficult to work with,” said Matt Canter, a spokesman for the Democratic Senate Campaign Committee. “He won’t be in the same room with [Republican senators], not even looking them in the eye when he tells them they need to jump off a cliff or do something else crazy. He is free from all the rules and ethics of governing, and he will be able to marshal hundreds of millions of dollars to further his agenda. Republicans still see him as the kingmaker.”

And with DeMint still having a handful of acolytes in the Senate, his move a few blocks away to Heritage shows how much the center of gravity of the party has shifted—a shift that owes a lot to the senator’s advocacy. In conservative circles, Heritage’s influence had begun to wane—it is the birthplace of the individual mandate, after all—as the GOP has grown ever more focused on shrinking the size of the government.

“DeMint is where the party is going,” said one GOP operative. “Heritage gets as their president the guy who is the intellectual heart of the party.”