More than $3.6 million has been dropped in the 4th Congressional District race by political parties and interest groups -- the third-highest amount spent by independent groups in any U.S. House race in the country.

Most of the spending has come from three groups - both parties' political fundraising arms, as well as the pro-environmental group Defenders of Wildlife Action Fund, according to the Fort Collins Coloradoan.

Independent spending against incumbent U.S. Rep. Marilyn Musgrave (R-Fort Morgan) has topped spending against Democratic opponent Betsy Markey by almost a 2.5-1 margin, the Coloradoan reported.

Musgrave manager Jason Thielman told the Coloradoan that Musgrave has been the target of a massive spending campaign to unseat her because of her support of a federal ban on gay marriage.

"The radical homosexual movement driven by Tim Gill hates Marilyn Musgrave, and they are willing to spend anything and everything to settle their vindictive agenda," Thielman said.
However, the three main independent groups involved in the race aren't  primarily focused on the gay marriage issue.

Defenders of Wildlife has spent $1.16 million to oppose Musgrave and another $200,000 in electioneering communications reports, according to the Coloradoan.

The National Republican Congressional Committee has spent $1.12 million on Musgrave's behalf, though it pulled its ad buys for the last week of the campaign. The Democratic Congressional Campaign Committee has dropped $1.11 million into the race to help Markey, according to the Coloradoan.

The congressional race with the most independent spending has been Michigan's 7th Congressional District, where $4.1 million has been spent in the race between incumbent Republican Tim Walberg and Democrat Mark Schauer.

The race in Pennsylvania's 11th Congressional District between Democratic incumbent Paul Kanjorski and Republican Lou Barletta came in second in the nation, with $3.76 million in independent spending.