About 20% of the country is unhappy with both sides- and they're leaning strongly toward the GOP. … The voters who hate everything and everyone are a key part of the electorate this year- and their support of the GOP is a big part of why the party's headed for a big victory.

Weigel put it this way yesterday:

Voters are only marginally more interested in GOP control of Congress than they are in retaining Democratic control of Congress, but they're passionately into the idea of destroying the Congress they have right now.