The evidence suggests that partisan polarization in the absence of supermajorities does not cause gridlock. What can and has caused it on so many important domestic policy issues has been electoral volatility. From the TARP example to a raft of others, it is clear that as long as enough congressional members with safe seats are prepared to hammer out deals across party and ideological lines, significant legislation can pass. Not only will this be true for the next Congress, it has been true for most recent ones, as a little historical review shows.
So is gridlock OUR fault as a nation, rather than the product of polarizing, selfish ideologues in DC? Have our electoral tastes become increasingly fickle over time? Or, as Barone goes on to discuss, is it the composition of our parties that is at fault? Either way, the effects of outside forces such as demographics, population movements, and voter mindsets cannot be underestimated as causes for the modern state of affairs in the nation's capital.