Yglesias on why, despite a near-supermajority, Democrats are having trouble making headway in Congress:
In foreign policy, liberals often believe that disputes with foreign actors can and should be settled through negotiation and compromise. That’s because international relations isn’t a zero-sum affair. Conflict is costly to both parties, good relations bring benefits to both parties, so disagreement is generally amenable to compromise. Ideological disagreement isn’t zero-sum either. Neither conservatives nor progressives are wedded to principles that require defense of wasteful Medicare spending. But partisan politics is zero-sum. A “win” for the Democrats is a “loss” for Republicans. And I the predominant thinking in the Republican Party at the moment is that inflicting legislative defeats on Democrats will lead to electoral defeats for Democrats. That makes the GOP hard to bargain with.
My guess is that it will take about two more election cycles of Republican defeat before Congress starts behaving in a “bi-partisan” fashion. As long as the GOP plays partisan politics, any good legislation coming out of Congress will be seen not as good for America, but as good for the Democratic Party, and bad for the GOP. Which isn’t much motivation to cooperate, is it?