ST. PAUL — From the moment Al Franken won his Senate seat by just 312 votes in 2008, Republicans began foretelling his doom in 2014, painting him as a perfect target in their effort to retake the chamber this fall.

The money hasn’t matched the talk yet. While millions of dollars in advertisements have poured into North Carolina, Louisiana, Alaska and Arkansas — from outside groups trying to unseat vulnerable incumbent Democrats and others defending them — there’s been just a trickle in Minnesota, where recently nominated GOP challenger Mike McFadden hopes to oust Franken.

“One of the issues that Mike has … is there are a lot of opportunities for Republicans. Normally, there’s only a few,” said Rob Jesmer, a Republican consultant and former executive director of the National Republican Senatorial Committee. “Everyone is trying to figure out where the greatest return on investment is.”

The money shows Franken’s seat is not yet a top target for Republicans: less than $200,000 in ad buys and mailers from groups on both sides in the Minnesota race, compared with more than $14 million in North Carolina and more than $10 million in other contested states, according to Federal Election Commission filings. But outside groups are watching, waiting to see if McFadden can make it a close race and turn the reliably Democratic state into a 2014 battleground.

In whiffs of what could come, the NRSC — Republicans’ main campaign arm in the Senate — hosted a fundraiser for McFadden in March attended by Senate Minority Leader Mitch McConnell. The former investment banker also has the U.S. Chamber of Commerce in his corner, promising to spend aggressively to beat Franken. Senate Majority Leader Harry Reid threw a fundraiser in Nevada over the weekend for Franken and a Senate candidate in Michigan seeking to keep the open seat in Democrat’s hands.

Jesmer said McFadden, a political newcomer, has proven himself a worthy candidate by winning the party’s endorsement and nomination and pulling in more than $3 million from donors before last week’s primary. McFadden has focused on small, cozy events to spread his name across Minnesota — later this week, he’ll wrap up a statewide tour by hitting all of Minnesota’s 87 counties.

He criticizes Franken for being too close to Obama and on energy policy, portraying him as being responsible for hold-ups in permitting a copper mine in northern Minnesota and the regulatory delays on the proposed Keystone XL pipeline. Franken said he supports the mine if it passes environmental reviews. He is undecided on the pipeline but has voted to follow the ongoing review process and would require it to be built with American steel.

Meanwhile, Franken has hardly engaged McFadden, instead pointing to bills passed during his five years in the Senate — a new farm bill chief among them — and the reputation he’s tried to build as a workman senator in asking for another term.

McFadden said he’s clearly different than Franken and will draw plenty of national support.

“This is a very important seat for the nation,” McFadden said. “We’ve already seen a dramatic increase and focus on this race. I expect that to continue.”

If polls show McFadden is closing in on Franken, Jesmer, whose firm has done some work for an anti-Franken super PAC, said big money will come regardless of whether Republicans have better prospects elsewhere.

“If the race becomes close, there’s going to be money in Minnesota. The money finds these competitive races,” Jesmer said.