Tom Harkin (IA)
Barbara A. Mikulski (MD)
Jeff Bingaman (NM)
Patty Murray (WA)
Bernard Sanders (I) (VT)
Robert P. Casey, Jr. (PA)
Kay R. Hagan (NC)
Jeff Merkley (OR)
Al Franken (MN)
Michael F. Bennet (CO)
Sheldon Whitehouse (RI)
Richard Blumenthal (CT)
Michael B. Enzi (WY)
Lamar Alexander (TN)
Richard Burr (NC)
Johnny Isakson (GA)
Rand Paul (KY)
Orrin G. Hatch (UT)
John McCain (AZ)
Pat Roberts (KS)
Lisa Murkowski (AK)
Mark Kirk (IL)