Who is Bluffing?

Sen. Kent Conrad (D-ND) recently reported that there has never been enough votes in the Senate for a 'robust' public option. That's interesting. Must be some of that 'new math' I used to hear about when I was a kid.

Ezra Klein gives us the play-by-play in the actual legislative steps that a reform bill faces. What he reminds us of is, once the bill leaves conference committee it goes to each chamber, if it has any public option it will pass the House, easy enough. Then we go to the anti-democratic, anachronistic US Senate where there are three options, vote yes or no, or filibuster. The Democrats control 60 seats, they need 60 votes to pass the bill, you can assume 55 of those (assuming Byrd and Kennedy can vote). The hold outs might include Ben Nelson, Kent Conrad, Joe Lieberman, Max Baucus, Mary Landrieu, and Arlen Specter. The Republicans that want a bill passed include Susan Collins, Olympia Snowe, and Richard Lugar. Then there are the dead-enders that are still in the debate (Chuck Grassley, John Kyl, Mike Enzi, Judd Gregg). The question, as Mr. Klein states, who is going to filibuster? Are they really willing to do this? Who is bluffing?