Liberal Democrats making empty threats

Would liberal Democrats really not vote for a bill without a public option? We're hearing threats that without a public option, 100 Democrats will vote against it, which would mean no health care bill at all, since a bill with a public option can't pass and a bill without one can't pass.

Personally, I don't think they would, and it's not about guts or spine, it's about incentives. the Blue Dogs come from districts that are against the public option vehemently. If no bill passes, it's no skin off their backs.

So that leaves liberals with an empty threat, and the Blue Dogs know it.