Rick Hasen has a really interesting paper up discussing partisan polarization and the possibility of changing the Constitution to deal with it. (And you should really read Jonathan Bernstein's response, too.) Hasen starts off by asking whether we should be considering moving toward a more parliamentary style of government.
It's a fair question. We have what looks like a serious mismatch between our parties and our governing institutions. We live in an era of sharply distinct, internally disciplined, programmatic parties with very different visions of how the nation should be run. That's fine—we have some time-honored institutions, such as elections and majority-rule legislatures, for settling disagreements, even when the disagreements are sharp.
But that's not all we have. Under our constitutional system, we have many rules designed to thwart majority rule and slow down lawmaking. A bicameral legislature and separation of powers, for example, are built into the system, with the explicit purpose of making it harder to pass laws—and over the years we've added things like the filibuster and debt ceiling votes that slow things down further. At times when parties are weak, as they were in the mid-20th century, it's possible for legislators to come together across party lines and work out agreements despite these impediments. But when parties are strong, the minority party has a lot of tools to keep the majority from accomplishing much of anything.
California is a great case study in this. For decades, the state has had an unusual feature: a two-thirds vote requirement for budget passage. It also has the most polarized legislature in the country. On top of that, much of the state's discretionary spending is dictated by a series of initiatives, placing it beyond the legislators' control. Finally, like most states, it must balance its budget every year. All of this makes for an explosive cocktail. Any time a recession causes a revenue shortfall, Democrats (usually the majority, but almost never controlling two-thirds of either chamber) seek to make up the gap by raising taxes. Republicans refuse to go along with this plan and demand to slash social services instead. The crisis usually gets resolved when one or two Republicans agree to vote for the Democratic budget (sacrificing their careers in the process) or when legislators figure out how to defer paying the bills without making it look like they're running a deficit. California looks vaguely governable right now, since Democrats managed to take over two-thirds of both chambers last year, but on the whole, the system is either in a crisis or heading for one just about every year.
Lots of political observers recognize that such governing systems don't work well alongside polarized parties, but their usual suggestion is to try to fix the party side of the equation. This rarely works. Efforts to curb legislative partisanship—including open primaries, redistricting reform, or bipartisan seating—have pretty weak track records. Partisanship is much bigger than that and can't just be wished away; efforts to stop it often do nothing and are sometimes counterproductive. (Indeed, here's a conference paper showing that switching to open primaries can create more polarized parties.)
Could we change the other side of the equation? That is, could we design governing institutions that work better with strong parties? James Madison, who pioneered a political theory in defense of inefficient government, would probably oppose such a move. The numerous check points in the Constitution that slow down legislation were features, not bugs. Then again, Madison isn't around anymore, and even if he were, he might well consider inefficient government a fine idea that got carried too far.
Could a parliamentary system be the way to go? And if so, how would we get there? Actually, getting there might not be too hard. Tom Schwartz at the University of California, Los Angeles is fond of noting that the U.S. Constitution could be interpreted as creating a parliamentary system. There's nothing (other than custom) preventing the Speaker of the House from functioning like a Prime Minister, with the President reduced to a largely ceremonial role and the Senate becoming a House-of-Lords-like body of entitled elites that defers to the lower chamber. We just haven't interpreted the Constitution that way so far.
Then again, it's not like a parliamentary system is a cure all. Besides, some relatively minor tinkering (maybe abolishing the filibuster?) could go a long way toward making the country a lot more governable. But it's worth remembering that our government wasn't designed to function very well. If we want to blame someone for gridlock, we might start with the people whose faces adorn our money.