And realistically, how many house/senate seats would the Dems have now without Obamacare? Would they really still have control of the Senate? I actually doubt it.
Democrats expected that the numbers would prevent them from losing, especially on this scale after 2008. Schumer even says that Republicans will ensure a Democratic majority sooner or later. His theory is that Republicans would not have been able to claim the Democrats were distracted from the economy by focusing on healthcare. As he said, the Republican have nothing to offer a country with falling incomes because they are philosophically opposed to useing gov't as a solution and therefore whenever Democrats advocate using the gov't to solve problems and Republicans do nothing or at least nothing coherent, the voters will give the Democrats a solid a majority in 2016.