Democrats only had to defend one open seat, in Iowa, where Democratic Secretary of State Chet Culver beat Republican U.S. Rep. Jim Nussle.

CNN: Majority of states have Democratic governor

Jim Nussle, a former congressman from Iowa, was nominated as his successor and will take on the job amid a strenuous budget battle on Capitol Hill.

ECONOMIST: Politics this week

Bush immediately tapped former Iowa congressman and gubernatorial candidate Jim Nussle to succeed Portman as director of the White House Office of Management and Budget (OMB).

FORBES: Magazine Article

"Just as we commend our troops, it is time to do our job, " said House Budget committee chairman Jim Nussle, after intense lobbying of moderate Republicans by Vice-President Dick Cheney and White House chief of staff Andrew Card.

BBC: Bush pursues guns and butter