Roger Wicker, the junior Senator from ruby red Mississippi, has never faced a competitive reelection campaign.  He hasn't made much of a name for himself in the Senate. And he's never had to make a hard appeal to independent voters.

So, how'd a three-term, low-profile Republican Senator become the man charged with re-electing his GOP colleagues in 2016? The answer could have something to do with lingering party concerns about an irksome electoral issue: primaries.

To win his post as head of the National Republican Senatorial Committee, Wicker had to convince his Republican colleagues to back him over Dean Heller, a Nevada Senator who's pitch to the caucus focused on his experience running in an increasingly competitive purple state. With 24 seats to defend and several in purple states like Colorado and Florida, the 2016 map heavily favors Democrats. To win, Republicans will have to broaden their appeal in places with demographics more like Nevada than Mississippi.

"I've been in tough races. I've been in tough primaries. I've been in tough generals. And I'm the only one in this race who has been," Heller told the National Journal. "So if they want someone who knows how difficult this next cycle is going to be, someone who won in a presidential cycle where the president won our state by 7 points and I still won, I think that's a pretty good pull. A pretty good answer for those who know they're going to have tough races, whether that's New Hampshire, Pennsylvania, Ohio, Wisconsin, Florida—those are going to be tough races, and we need someone in there that has that kind of experience."

But Wicker does have an awful lot of experience in one particularly part of the political arena: primaries. He won his first House election in 1994 by prevailing in a six-way primary contest. And while Heller, like many of his colleagues, stayed out of primary contests this year, Wicker was a major force in Thad Cochran's run-off campaign, raising an impressive $750,000 to help the seven-term Senator fend off a Tea Party challenge from Chris McDaniel. "He was the superstar of all superstars for Senator Cochran in that run off and I think all his colleagues were playing attention," said Austin Barbour, a Mississippi political consultant who ran Cochran's run-off effort. 

Wicker even went so far as to blast the conservative groups that spent money on challengers like McDaniel. "I’m mystified that the powers that be at some point felt that that was a good expenditure of scarce campaign resources," he told the Washington Post.

Wicker's efforts helped make him one of the party's top fundraisers in 2014, with a total haul of more than $5.3 million for his own committees, according to the Center for Responsive Politics. He raised well over $2 million at nearly 50 events for the NRSC this year, according to people close to the Senator. An ally of former governor Haley Barbour (who appointed him to his Senate seat in 2007), Wicker can tap Barbour's lucrative fundraising network. And he's close with Karl Rove, who's American Crossroads will be a key organization for Republicans in 2016. The two first met in early 1970s when Rove was campaigning for chairman of the National College Republicans. 

The relatively limited field also helped his chances: Much of the Republican caucus  is either up for reelection in 2016 or running for president, or both.

Speaking on Capitol Hill today, Wicker promised to expand on the party's successes this year.

"We’re determined that we build on the success we had in 2014 for the 2016 cycle. That includes protecting our 24 incumbents, increasing our majority, and making it possible to elect a Republican president," Wicker said.  

This year's results will certainly give him at least one advantage. Even though the map may be tougher for Republicans, Wicker starts from a much more comfortable position than his predecessor, Ohio Senator Rob Portman faced. Republicans now control 54 seats, giving Wicker a four seat cushion on controlling the Senate.