Here's a letter written 2 1/2 years ago and signed by 20 senators. The first four signers are Chuck Hagel (R-Nebraska), John Sununu (R-New
Hampshire), John McCain (R-Arizona) and Elizabeth Dole (R-North Carolina).
I don't know who that 5th signature belongs to, but the other 15 signers are:
Jeff Sessions (R-Alabama)
Wayne Allard (R-Colorado)
Mike Crapo (R-Idaho)
Jim Bunning (R-Kentucky)
Jon Kyle (R-Arizona)
Rick Santorum (R-Pennsylvania)
Mel Martinez (R-Florida)
Judd Gregg (R-New Hampshire)
John Thune (R-South Dakota)
Richard Burr (R-North Carolina)
John Ensign (R-Nevada)
Larry Craig (R-Idaho)
Jim DeMint (R-South Carolina)
James Inhofe (R-Oklahoma)
Tom Coburn (R-Oklahoma)
Edit to add: Dagnabbit, TheRooster beat me to it.
[edit on 12-10-2008 by Tuning Spork]