Mike Pence (R-Ind.)
Pence won't run for president, but he's all-but-in for governor in 2012. Former Wayne County Sheriff Matt Strittmatter
(R) has been raising money for the seat since last June, but other
Republicans are also eyeing the seat in what's likely to be a crowded
primary. Other possible GOP candidates include Pence's predecessor,
former Rep. David McIntosh, and former state Rep. Luke Messer, who mounted an aggressive challenge to neighboring 5th District Rep. Dan Burton (R) in 2010. Democrats won't write off the seat just yet, pointing to former Sen. Evan Bayh's (D) routinely strong performances here.
Jay Inslee (D-Wash.)
Inslee's widely expected to run for governor in 2012, but his district should remain in Democratic hands, even if it's drawn differently after Washington adds another congressional seat.
Joe Donnelly (D-Ind.)
Donnelly had one of the closest elections in the country in 2010, and his former foe Jackie Walorski (R) is likely to run again. Donnelly may fare better in a race for governor, although it would still be an uphill battle against the popular Rep. Pence. How many new Republicans the state legislature adds to Donnelly's district will play a big role in determining which way he leaps.
Michael Capuano (D-Mass.)
Capuano already made a run for the Senate seat once, but he didn't have to quit his House seat when he ran in a special election in 2009. He's one of a handful of Bay State Democrats weighing whether to take on Sen. Scott Brown, but early polling has still shows him trailing. His House seat would stay firmly in the Democratic column.
Dean Heller (R-Nev.)
The three-term Reno congressman is openly considering a primary challenge to the scandal-marred Sen. John Ensign (R) -- and early polling indicates he's likely to win both the GOP nomination and the general election. Still, Heller held back when all evidence showed he would have beaten Senate Majority Leader Harry Reid (D) in 2010.
Check out Taylor's full lists here.(Subscription required).