A new study from Maplight.org, a "nonpartisan, nonprofit research group illuminating the connection between money and politics," reports that "U.S. House members raised $700 million in campaign funds," during the 2005-2007 time period, with 79%, or $551 million of that amount coming from outside the district of the House member running for office.
According to Maplight, around 21% of campaign contributions to U.S. House members originated in Washington, D.C., with Virginia, California, New York, and Texas rounding out the top five source locations for contributions. The reports states that the majority of campaign funds not only came from out of district, but out of state sources as well:
About two-thirds of House members, 274 out of 421 (65%), raised half or more of their funds from out-of-state. Ninety-two House members (22%) raised 70% or more of their funds from out-of-state. Eight House members raised 90% or more of their funds from out-of-state. The average percentage of funds each Representative raised from out-of-state is 56.7%, and the median percentage is 56.1%.
It should be noted that the Maplight report only looks at donations of over $200, the point above which the donor must be identified to the Federal Elections Committee. Much has been made of the move, particularly by the Obama campaign, towards utilizing a base of small donations, under this $200 dollar threshold. Estimates place somewhere between one quarter and one half of Sen. Obama's $600 million of campaign contributions in this class.
This potential move towards smaller donations does not appear to have had as much of an impact on Congressional races. According to the Campaign Finance Institute, registered candidates for the U.S. House raised $447 million in the first four months of 2008, with "less than 10% of this total [arriving] in amounts of $200 or less." This, states the CFI, marks little or no change from prior years.