When it comes to the House, Republicans don’t need a wave.  Via Charlie Cook:

One might have expected that two years after Republicans picked up 63 House seats—the biggest gain in a midterm election since 1938—Democrats would be on track to win back a boatload of those districts that the GOP didn’t have much business winning in the first place. But a little more than four months out from the election, the tides seem about as neutral as they can be. Both parties have surprisingly comparable levels of exposure, largely because of redistricting. The relatively calm surface of this year’s waters belies a lot of offsetting tumult and change underneath. But for House Republicans, who hold a 25-seat majority, a status quo election producing minimal net change would be good news.

When it comes to the House that may be right, but we still need a wave to take back the Senate, and to do so by more than a 1-vote margin which leaves us at the mercy of the weakest link.

And we also need that wave to overcome the structural advantages Obama has (sure win in several large electoral states, incumbency, people wanting free stuff, etc.).

So wave.