This midterm election season has marked a record year for campaign spending.

Earlier this year, the Supreme Court opened the way for corporations and unions to spend money in elections. So far, outside groups have spent $264 million for the upcoming Nov. 2 elections.

The number -- reported to the Federal Election Commission -- shows more outside spending than in the 2008 presidential campaign and four times more outside spending than in the 2006 midterms.

The Democratic Party maintains a financial edge over the GOP, but an Associated Press analysis of FEC data revealed Democratic allies have virtually pulled even with Republican groups in spending during the past six days.