In Minnesota's First District, outside spending from the national parties as well as independent groups like former U.S. Sen. Norm Coleman's American Action Network has topped $1 million, according to Federal Election Commission records.

Most of the money has been used to oppose Rep. Tim Walz, as six groups have combined to spend $838,000 either opposing Walz or supporting his challenger, state Rep. Randy Demmer. Walz has received outside support from two groups spending $169,000 so far.

The onslaught of outside spending is one gauge of how competitive both sides view the First District race.

The biggest spenders have been the party congressional committees. The National Republican Congressional Committee has put more than $527,000 into advertising and polling in the First District, while the Democratic Congressional Campaign Committee has pledged to spend more than $275,000, according to national Democrats (the DCCC has spent $126,000 so far).

The Republican Party of Minnesota has put $30,000 into the race through independent expenditures.

Outside groups are spending money on the race in two different ways. Political committees Super PAC for America, National Right to Life and Bluegreen Alliance have spent money on independent expenditures, which can directly endorse or oppose candidates but cannot coordinate with campaigns. They have spent $106,000 combined — $22,000 backing Walz, $84,000 backing Demmer.

Coleman's group, the American Action Network, is a non-profit advocacy group that has put $175,000 into the First District against Walz through "electioneering communications," broadcast ads that mention federal candidates but don't specifically ask viewers to vote for or against a candidate.