Tom Harkin (IA)
Barbara A. Mikulski (MD)
Patty Murray (WA)
Bernard Sanders (I) (VT)
Robert P. Casey, Jr. (PA)
Kay R. Hagan (NC)
Al Franken (MN)
Michael F. Bennet (CO)
Sheldon Whitehouse (RI)
Tammy Baldwin (WI)
Christopher S. Murphy (CT)
Elizabeth Warren (MA)
Lamar Alexander (TN)
Michael B. Enzi (WY)
Richard Burr (NC)
Johnny Isakson (GA)
Rand Paul (KY)
Orrin G. Hatch (UT)
Pat Roberts (KS)
Lisa Murkowski (AK)
Mark Kirk (IL)
Tim Scott (SC)