According to this article in the Atlantic by James Fallows which reference another article on Bloomberg by Joshua Green, the president has the upper hand
The reasoning is below the orange squiggle
"Despite their post-election tough talk, Republican leaders have dealt themselves a lousy hand. Obama can propose a "middle-class tax cut" for the 98 percent of American households earning less than $250,000 a year -- while letting the Bush tax cuts expire for those earning more -- and dare the Republicans to block it. If they do, everyone's taxes will rise on Jan. 1.
It's true that going over the fiscal cliff, as some Democrats believe will happen, would set back the recovery and could eventually cause a recession. But Democratic leaders in Congress believe the public furor would be too intense for Republicans to withstand for long.*