The gamble is three-fold: that Senate Majority Leader Harry Reid will cave; that Republicans will get a better deal in the next two weeks than they will in two months; and third, that if the payroll tax cut expires they'll manage to spin their way out of the blame for it.
Part of that spin will rest on the convoluted procedure Republicans used to reject the Senate compromise. They didn't give that bill an up-or-down vote. They gave it a down-or-down vote. The question before the House wasn't "do you agree with the Senate bill?" It was "do you disagree with the Senate bill?" Thus a "yes" vote was actually a vote against extending the payroll tax cut and vice-versa; and even if the majority of the House had supported the Senate bill, it wouldn't have passed. It was set up to fail.
In the lead up to Tuesday's vote, Senate Democrats expressed a great deal of confidence that they would win the battle for public perception. Now the question is whether they truly believed that, and will keep up the brinkmanship -- even if it means allowing the payroll cut lapse temporarily -- or whether, under pressure from House Republicans, they'll come back to the Capitol and begin yet more negotiations on yet another compromise.
Both Reid and House Minority Leader Nancy Pelosi have said publicly they have no intention of reopening negotiations. But if they do, they'll have an awful lot of leverage. As the 2011 calendar thins out, and the possibility that the payroll tax will expire becomes more and more real, they'll be able to point to the Senate compromise -- which got 89 votes -- and demand Republicans offer them a better deal than that.