The latest NBC/Wall Street Journal poll shows that the Democratic Party remains considerably less unpopular (33% positive/44% negative) than the Republican Party (24% positive/46% negative.) Both are less popular than President Obama. Yet everybody believes the less popular party is going to gain a lot of seats in the fall elections.

There are a couple lessons to this paradox that Washington conventional wisdom has not grasped. First, for the umpteenth time, structural conditions (like a midterm and the economy) have vastly more importance than the voters ideological discernment of which party is closer to their issue preference.

Second, midterm elections are a referendum on the majority party. During the first couple years of the Bush administration, moderate Democrats were frequently afraid that opposing the president would make them look partisan. And, indeed, exactly this fate has befallen the 2009-2010 GOP. They look partisan. Everybody hates them. But it doesn't matter. What the opposition party does matters to the extent that it effects 1) real-world conditions, and 2) the majority party's standing. Withholding support makes the process messier and more partisan. Republicans may come away looking dirtier, but that won't hurt them.

I don't want to give the impression that Republican legislative tactics are what will win them seats in November. They were bound to do well regardless. But throwing sands in the gears and denying Obama bipartisan accomplishments has proven to be an unremitting success. This is the successful model of opposition party behavior.