The following ratings were released 4 June 2008:
The current makeup of the U.S. Senate is 49-49 with 2 Democratic-leaning Independents, giving the Democrats a 51-49 majority. In 2008, 12 Democratic and 23* Republican seats are up for election.
* two of these seats are to fill unexpired terms.
Democrats:
The following Democratic seats are rated Safe: (10) Arkansas [...]

The following ratings were released 29 August, 2007:
The current makeup of the U.S. Senate is 49-49 with 2 Democratic-leaning Independents, giving the Democrats a 51-49 majority. In 2008, 12 Democratic and 22 Republican seats are up for election.
Democrats:
The following Democratic seats are rated Safe: (6) Delaware (Biden), Illinois (Durbin), Massachusetts (Kerry), Michigan (Levin), Rhode Island [...]

The following ratings were released 21 May, 2007:
The current makeup of the U.S. Senate is 49-49 with 2 Democratic-leaning Independents, giving the Democrats a 51-49 majority. In 2008, 12 Democratic, and 21 Republican seats are up for election.
Democrats:
The following Democratic seats are rated Safe: Delaware (Biden), Illinois (Durbin), Massachusetts (Kerry), Michigan (Levin), Rhode Island (Reed) [...]

The following ratings were released 5 April, 2007:
The current makeup of the U.S. Senate is 49-49 with 2 Democratic-leaning Independents, giving the Democrats a 51-49 majority. In 2008, 12 Democratic, and 21 Republican seats are up for election.
Democrats:
The following Democratic seats are rated Safe: Delaware (Biden), Illinois (Durbin), Massachusetts (Kerry), Michigan (Levin), Rhode Island (Reed) [...]