In Minnesota's Seventh Congressional District race, Democratic U.S. Rep. Collin Peterson and his Republican challenger, Torrey Westrom, stepped up their fundraising during the months of April, May and June.

Peterson raised $268,000 during the quarter and has $717,300 banked for his re-election bid. The top Democrat on the House Agriculture Committee, Peterson is seeking a 13th term in Congress.

Westrom raised nearly $231,500 and has almost $327,800 cash-on-hand. The attorney and state senator, announced his candidacy in early December.

The second quarter marked the best fundraising period of the election cycle for both candidates.

Westrom has the backing of the national Republicans, who consider Peterson vulnerable because he hails from a district that backed Republican candidate Mitt Romney in the 2012 presidential election. The seat covers much of western Minnesota from the Canadian border down to southern part of the state.

This spring, the National Republican Congressional Committee named Westrom to its "Young Guns" program for promising candidates.

Despite the district's conservative tilt, Republicans challengers haven't posed much of a threat to Peterson, a conservative Democrat who has coasted to re-election for much of the past 20 years.