Arkansas
Incumbent: Mark Pryor (first elected in 2002)
CQPolitics rating: Democrat Favored
Rachel Kapochunas
Delaware
Incumbent: Joseph R. Biden Jr. (first elected 1972)
CQPolitics rating: Safe Democratic
Greg Giroux
Illinois
Incumbent: Richard J. Durbin (first elected 1996)
CQPolitics rating: Safe Democratic
Greg Giroux
Iowa
Incumbent: Tom Harkin (first elected in 1984)
CQPolitics rating: Democrat Favored
Greg Giroux
Louisiana
Incumbent: Mary Landrieu (first elected in 1996)
CQPolitics rating:
Leans Democratic
Greg Giroux
Massachusetts
Incumbent: John Kerry (first elected in 1984)
CQPolitics rating: Safe Democratic
Adam Bloedorn and Bob Benenson
Michigan
Incumbent: Carl Levin (first elected in 1978)
CQPolitics rating: Safe Democratic
Marie Horrigan
Montana
Incumbent: Max Baucus
CQPolitics rating: Democrat Favored
Marie Horrigan
New Jersey
Incumbent: Frank R. Lautenberg(first elected in 1982, did not serve 2001-03, elected to return to Senate in 2002)
CQPolitics rating: Democrat Favored
Rachel Kapochunas
Rhode Island
Incumbent: Jack Reed (first elected 1996)
CQPolitics rating: Safe Democratic
Marie Horrigan
South Dakota
Incumbent: Tim Johnson (first elected in 1996)
CQPolitics rating: No Clear Favorite
Marie Horrigan
West Virginia
Incumbent: John D. Rockefeller IV (first elected 1984)
CQPolitics rating: Safe Democratic
Greg Giroux