WASHINGTON – Jeff Larson has been called the silver bullet in Minnesota GOP politics, the smartest guy in the room, a close friend and political adviser for myriad Republican pols coming up through the ranks.

With that rep among GOP higher-ups, the South Dakota native with three decades of experience has gone national. He is contracted to run the independent expenditure arm of the National Republican Senatorial Committee — charged with getting Rs elected to the U.S. Senate this November.

This means that while he has a firewall between his organization and the campaigns themselves, he will steer somewhere in the neighborhood of $35 million in any direction he wishes to try and shift the Senate red. (This number is subject to fundraising prowess.)

In a rare interview, Larson said he likes his job because it’s hard. Republicans are trying to leverage an unpopular president to gain seven or eight Senate seats and take over the leadership of the chamber. Keeping GOP leadership in the House is all but certain, but control of the narrowly split U.S. Senate is up for grabs.

“This job, as well as the Minnesota Action Network, is a lot of work but very rewarding, given what is at stake,” he said.

He is largely credited with helping the 2008 Minneapolis-St. Paul Host Committee as it struggled to raise cash for the Republican National Convention. In a famous save, Larson ended up with a bill for more than $130,000 to bedeck then-veep nominee Sarah Palin in new clothes. He says the Republican National Committee eventually paid him back.

Larson, who worked with former Sen. Norm Coleman through his recount fight against Al Franken in 2009, said he took some of those lessons from that battle that stretched through the summer and to the Minnesota Supreme Court.

“Jeff Larson is the smartest, most well-connected guy in Minnesota politics that no one knows,” Coleman said. “He is a close personal friend and an adviser.”

In his current gig, Larson leaves D.C. weekly and commutes to Wisconsin, where he has a wife and two kids.

“This place is such a bubble,” he said, referring to the Beltway. “You go back and hear what people are talking about and it’s nothing like the conversations that are happening in D.C.”

Larson keeps a famously low profile and is known among operatives for being even-keeled, despite the pressures of copious fundraising demands and a constant-churning campaign cycle.

He said he is pleased with Minnesota’s GOP Senate candidate Mike McFadden, who is raising money and ingratiating himself to the Minnesota Republican base. Larson said he didn’t think national operatives believed the race in Minnesota would be set so early. By the time the Republican convention was over in Rochester, McFadden was the endorsed candidate, which has taken a little while for national people to figure out, Larson said. He expects the Minnesota race to heat up — particularly if other close races across the country start showing bigger leads. (McFadden still has a not-very-well-funded primary challenger in Republican state Rep. Jim Abeler.)

Larson said he has taken his greatest political life lessons from losing.

“When you lose, you think about what could I have done better, what could I have done differently?” he said. “When you win, you feel like you did everything right.”