

John Shadegg, representing Arizona's 3rd congressional district, will retire in 2010. Shadegg's district has leaned Republican by 9 percentage points in the previous two presidential elections. The Cook Political Report rates this a 'Likely Republican' district.
John Boozman, representing Arkansas's 3rd congressional district, is running for Senate in 2010. This district has leaned Republican by 16 percentage points in the previous two presidential elections. According to the Cook Report, 'This northwestern Arkansas seat has consistently been the fastest-growing and most Republican district in the state.'
George Radanovich, representing California's 19th congressional district, will retire this year. Radanovich's district has leaned Republican by 9 percentage points in the previous two presidential elections. According to the Cook Report, 'President Obama carried eight districts held by California Republicans, but this rural patchwork of Central Valley towns wasn't one of them.'
Mike Castle, representing Delaware's At-large congressional district, will make a bid for the Senate this year. Castle's district has leaned Democratic by seven percentage points in the previous two presidential elections. The Cook Political Report rates this a 'Lean Democratic' district.
Adam Putnam, representing Florida's 12th congressional district, is running for Florida Commissioner of Agriculture in 2010. This district has leaned Republican by six percentage points in the previous two presidential elections. The Cook Political Report rates this a 'Likely Republican' district.
Lincoln Diaz-Balart, representing Florida's 21st congressional district, will retire this year. This district has leaned Republican by five percentage points in the previous two presidential elections. The Cook Political Report rates this a 'solidly Republican' district.
Mario Diaz-Balart, representing Florida's 25th congressional district, will attempt a rare district-swap in 2010, running in Florida's 21st district for a seat to be vacated by his brother. This district has leaned Republican by five percentage points in the previous two presidential elections. According to the Cook Report, 'The Diaz-Balart family is political royalty in this district and Mario Diaz-Balart is a strong favorite to succeed his brother. '
Nathan Deal, representing Georgia's ninth congressional district, is running for Governor of Georgia this year. Deal's district has leaned Republican by 28 percentage points in the previous two presidential elections. According to the Cook Report, 'This northwest Georgia district is the most Republican in the state, and the fourth most Republican in the nation.'
Mark Kirk, representing Illinois's tenth congressional district, will run for Senate in 2010. Kirk's district has leaned Democratic by six percentage points in the previous two presidential elections. The Cook Political Report rates this a 'Republican Toss Up' district.
Steve Buyer, representing Indiana's fourth congressional district, will retire in 2010. Buyer's district has leaned Republican by 14 percentage points in the previous two presidential elections.
Jerry Moran, representing Kansas's first congressional district, will make a Senate bid this year for a seat to be opened after Sen. Sam Brownback's departure. Moran's district has leaned Republican by 23 percentage points in the previous two presidential elections. The Cook Report characterizes this district as 'solidly Republican.'
Todd Tiahrt, representing Kansas's fourth congressional district, will make a Senate bid this year, also for Brownback's seat. Tiahrt's district has leaned Republican by 14 percentage points in the previous two presidential elections. The Cook Report characterizes this district as 'solidly Republican.'
Pete Hoekstra, representing Michigan's second congressional district, will retire. This district has leaned Republican by seven percentage points in the previous two presidential elections. The Cook Political Report rates this a 'strongly Republican' district.
Vern Ehlers, of Michigan's third congressional district, will retire this year, as well. Ehlers's district has leaned Republican by six percentage points in the previous two presidential elections. The Cook Political Report rates this a 'strongly Republican' district.
Roy Blunt, of Missouri's seventh congressional district, will run for Senate this year. This district has leaned Republican by 17 percentage points in the previous two presidential elections. The Cook Political Report rates this a 'strongly Republican' district.
Mary Fallin, representing Oklahoma's fifth congressional district, is running for Governor of Oklahoma this year. Fallin's district has leaned Republican by 13 percentage points in the previous two presidential elections. The Cook Report characterizes this district as 'solidly Republican.'
Henry Brown, representing South Carolina's first congressional district, will retire in 2010. Brown's district has leaned Republican by ten percentage points in the previous two presidential elections. The Cook Political Report rates this a 'Likely Republican' district.
Gresham Barrett, representing South Carolina's third congressional district, is running for Governor of South Carolina. Barrett's district has leaned Republican by 17 percentage points in the previous two presidential elections. The Cook Report characterizes this district as 'solidly Republican.'
Zach Wamp, representing Tennessee's third congressional district, is running for Governor of Tennessee this year. Wamp's district has leaned Republican by 13 percentage points in the previous two presidential elections. According to the Cook Report, 'This Chattanooga-based district has become so Republican in federal elections that it's easy to forget a Democrat, Marilyn Lloyd, held it as recently as 1994.'
Rep. Mark Souder of Indiana resigned from Congress after admitting to having an affair with a staffer. The religious conservative eight-term congressman was elected on a family values platform during the 1994 Republican revolution.