Former State Rep. Ed Fallon of Des Moines will be challenging Rep. Leonard Boswell in a primary in Iowa's 3rd district.
Boswell has been named a Bush Dog Democrat by Open Left, as one of the Democratic Rep's that supports Bush the most.
Fallon won a surprising 3rd place finish in the 2006 Democratic primary for Governor by building a strong grassroots organization. He won 26% when he was expected to get less than 5% at the start of the campaign. Fallon won Polk Co. and was the top vote getter in the 3rd district.
Fallon is socially liberal and fiscally conservative. He has pushed public financing of elections, universal health care, ending corporate tax give aways, and has never taken money from lobbyists and PAC's.
The caucuses showed there is a populist wave riding across Iowa and Fallon could ride that to Congress.
Here is some more background info.