WASHINGTON -- A top Republican campaign operative said Wednesday that Minnesota Democratic Reps. Collin Peterson and Rick Nolan are beatable this fall.

Nolan, of the 8th Congressional District, beat out an incumbent Republican in 2012 when President Obama swept the state. He previously served in the U.S. House of Representatives between 1975 and 1981.

National Republican Congressional Committee Chairman Rep. Greg Walden said in a sit-down with reporters that Nolan has taken "unfavorable" votes on veterans issues that "won't play well" in northern Minnesota.

He also spoke highly of Stewart Mills, the millionaire businessman vying to unseat him.

"Mills has developed a strong following both online and off and will have the resources necessary to run a competitive race," said Walden, a Republican congressman from Oregon. "I think Stewart is going to give Nolan a real run for his money."

On Peterson, Walden said the veteran chair of the House Agricultural Committee "hasn't run an effective race since 1994."

Peterson is a Democratic outlier in the district, which has voted Republican in the last three presidential races. GOP state Sen. Torrey N. Westrom is running against him.

"This is a district that wants to vote Republican," Walden said. "They haven't had as viable choice to run for Congresss as they do this time with Torrey."

"Representatives Nolan and Peterson are strongly positioned in their races because they are on the side of middle class Minnesotans," said Brandon Lorenz of the Democratic Congressional Campaign Committee. "Stewart Mills' suggestion that he is offended when millionaires like himself are asked to pay their fair share makes it clear he would side with Congressman Ryan's budget that raise taxes on the middle class to pay for tax cuts for millionaires like himself. Torrey Westrom has a long track record of irresponsibly selling out the middle class, especially when he voted to slash early childhood education when we need to invest in preparing our kids for the high-tech 21st century economy."