04/25/2010 05:12 am ET | Updated May 25, 2011

2010 Midterm Elections To Be Most Expensive Ever: Analysis

The upcoming midterm elections will cost at least $3.7 billion, making them the most expensive midterm elections of all time, according to an analysis by the nonpartisan Center for Responsive Politics.

"With so much on the line, the outpouring of big money into federal campaigns looks likely to continue at a brisk pace," said CRP's Sheila Krumholz in a statement.

CRP calls its estimate "conservative." The number is based on spending trends for Senate and House candidates, political parties, and outside groups known as 527 committees and political action committees during the past four midterm elections, which tends to increase by between 31 percent and 35 percent.

The 2006 midterms cost $2.8 billion, the 2002 midterms cost $2.1 billion, and the 1998 midterms cost just $1.6 billion. The amount spent by the average winning candidate has followed a similar pattern, with winners outspending losers in a big way. That, of course, is why members of Congress spend so much of their time on fundraising.

CRP's analysis doesn't include corporate spending on political advertisements, which is expected to be massive this year after the Supreme Court struck down the FEC's restrictions on "electioneering communications." Krumholz said the Supreme Court's decision "could precipitate millions more in spending by special interest groups looking to advance their own agendas."

Even before the Supreme Court's decision, more than 100 members of Congress signed on to the Fair Elections Now Act, which would create a system of public financing for congressional campaigns.

As for the money in campaigns, a lot of it comes from small donors, individuals who mail $100 to their preferred candidate's campaign committee. Most of it, however, comes from big-time donors, some of whom recently sent a letter urging congressional leadership to pass laws providing for public financing of campaigns.

It's not just elections that are drowning in cash, but the legislative process as well. CRP, the preeminent gatherer of data on money in politics, recently confirmed that 2009 was the most profitable year ever for the lobbying industry.