Iowa -- OPEN, Gov. Tom Vilsack (D) is retiring: This race drops
a spot solely because of Romney's announcement. Republicans have a right
to feel good here as Rep. Jim Nussle (R) is running a strong campaign
(though Bob Vander Plaats's (R) campaign is showing some life, attacking
Nussle on his stewardship of the nation's budget while in Congress). The
Democratic race is more wide open, although secretary of state Chet Culver
seems to be bouncing back from a slow start; Culver also likely got a
boost from a recent independent poll that showed him giving Nussle the
closest race of any of the announced Democrats. (Previous ranking: 3.)