Open seats

Kansas (Brownback-R) - Sen. Sam Brownback announced in 2005 that he will honor his self-imposed term-limit pledge and not seek re-election in 2010. Brownback is reportedly exploring a presidential bid for 2008.

Retirement watch

Alabama (Shelby-R) - Shelby was born May 6, 1934, and will be 76 on election day in 2010.

Arizona (McCain-R) - Born August 29, 1936, McCain will be 74 on election day in 2010. McCain is also reportedly considering a run for president in 2008.

California (Boxer-D) - Born Nov. 11, 1940, Boxer will be nearly 70 on election day in 2010.

Hawaii (Inouye-D) - Born Sept. 7, 1924, he'll be 86 years old on election day in 2010.

Iowa (Grassley-R) - Born Sept. 17, 1933, Grassley will be 77 on election day in 2010.

Kentucky (Bunning-R) - Born Oct. 23, 1921, Bunning will be 89 on election day in 2010.

Maryland (Mikulski-D) - Born July 20, 1936, Mikulski will be 74 on election day in 2010.

Missouri (Bond-R) - Born March 6, 1939, Bond will be 71 on election day in 2010.

Nevada (Reid-D) - Born Dec. 2, 1939, Reid will be nearly 71 on election day in 2010.

North Dakota (Dorgan-D) - Born May 14, 1942, Dorgan will be 68 on election day in 2010.

Ohio (Voinovich-R) - Born July 15, 1936, Voinovich will be 74 on election day in 2010.

Pennsylvania (Specter-R) - Born Feb. 12, 1930, Specter will be 80 in 2010. In Feb. 2005, Specter announced that he has Hodgkin's lympoma and will have to undergo 26 weeks of chemotherapy. Specter's doctor expects him to make a full recovery.

Utah (Bennett-R) - Born Sept. 18, 1933, Bennett will be 77 on election day in 2010.

Vermont (Leahy-D) - Born March 31, 1940, Leahy will be 70 on election day in 2010.

Safe (for now!)

Arkansas (Lincoln-D) - Born Sept. 30, 1960

Alaska (Murkowski-R) - Born May 22, 1957

Colorado (Salazar-D) - Born March 2, 1955

Connecticut (Dodd-D) - Born May 27, 1944

Florida (Martinez-R) - Born October 23, 1946

Georgia (Isakson-R) - Born December 28, 1944

Idaho (Crapo-R) - Born May 20, 1951

Illinois (Obama-D) - Born Aug. 4, 1964

Indiana (Bayh-D) - Born Dec. 26, 1955

Louisiana (Vitter-R) - Born May 3, 1961

New Hampshire (Gregg-R) - Born Feb. 14, 1947

New York (Schumer-D) - Born Nov. 23, 1950

North Carolina (Burr-R) Born Nov. 30, 1955

Oklahoma (Coburn-R) - Born March 14, 1948.

Oregon (Wyden-D) - Born May 3, 1949

South Carolina (DeMint-R) - Born Sept. 2, 1951

South Dakota (Thune-R) - Born January 7, 1961

Washington (Murray-D) - Born Oct. 11, 1950

Wisconsin (Feingold-D) - Born March 2, 1953

Updated June 19, 2005