Up to 3, depending on how you count, although most political experts would say 2.
Senator Bernie Sanders of Vermont is an Independent who caucuses with the Democrats. He has always run as an Independent in both his House and Senate races.
Senator Joe Lieberman of Connecticut is listed as an "Independent Democrat". He is a former Democrat who was defeated in the Democratic primary in 2006 and won the general election as an independent. He caucuses with the Democrats.
Senator Lisa Murkowski of Alaska lists herself as a Republican, but won re-election in 2010 as a write-in candidate after being defeated in the Republican primary. She still calls herself a Republican and caucuses with the Republicans.
There are 100 voting members in the Senate.
There are 56 members in the senate
there are 100 members in the senate
There are 100 members in the Senate (Senators), two for each state.
The Senate of Puerto Rico has 31 members.
there are 34 members
100 members
2 members in the senate, because there are 2 per state.
The Spartan senate (Gerousia) comprised 30 members.
there's 1 independent (Bernie Sanders) and 1 independent democrat (Joe Lieberman)
there are 45
50