Updated

The 2010 campaign is just under way, but a new report today suggests it will be the most expensive midterm election by far.

The nonpartisan Center for Responsive Politics estimates that the November elections will cost at least $3.7 billion -- about 30 percent more than the 2006 midterm elections when Democrats swept into power on Capitol Hill.

The fact that this election will set a record isn't surprising: Each election tends to cost more than the previous comparable campaign.

According to the center's data, the cost of midterm elections has grown from $1.6 billion in 1998 to $2.2 billion in 2002 to $2.85 billion in 2006.

Click here to read more at The Wall Street Journal.