National Republicans are homing in on Democratic U.S. Rep. Rick Nolan's seat in northern Minnesota.

On Thursday, the National Republican Congressional Committee added Nolan's challenger, Stewart Mills III, to the lowest level of its "Young Guns" program, which lends help to GOP candidates.

Mills was one of 36 House hopefuls named to the "On the Radar" list. If Mills reaches the next step, he would become a "Contender." The most promising candidates are tagged as "Young Guns."

As candidates ascend the ranks, they're more likely to receive financial and campaign aid from the NRCC and other members of Congress. Mills already outraised Nolan by nearly $100,000 during the last fundraising quarter.

The NRCC, the campaign arm of House Republicans, hopes to bolster GOP prospects in next year's mid-term elections by making the Affordable Care Act their primary campaign issue. In October, the group aired radio ads in Nolan's Eighth Congressional District, criticizing him for refusing to defund the health care law.

"With ObamaCare's bad policies and botched rollout affecting families across our nation, and our country diving deeper into debt each and every day, it's time to bring real change backed by conservative principles and priorities to Washington," NRCC chairman Greg Walden said in a statement Thursday.

"I am confident that these candidates will continue to work hard for their communities and their campaigns as we head into the 2014 election year."

In a press briefing this week, Democratic Congressional Campaign Committee chair Steve Israel said he is confident Nolan will defend his seat.

The NRCC has also targeted U.S. Rep. Tim Walz in the First Congressional District, but none of his potential Republican challengers made the up-and-coming list.