Glen Bolger of Public Opinion Strategies (via Pete Wehner at Contentions):
The generic ballot shows Republicans leading 44%-39%. Besides all of the usual regional crosstabs, we also broke it out by the type of district. We looked at the sample in the 66 Democratic INCUMBENT districts that Charlie Cook lists as either toss-up or leaning Democratic at the time of the survey. In that key crosstab of Swing Democratic Incumbent Seats, the Republican lead grows to 49%-31% on the generic ballot. That is a very powerful crosstab that says the wave is coming.
Among the remaining Democratic districts (Likely/Safe Dem, and open seats), the generic ballot is an unsurprisingly 33% GOP/51% Dem — a sign that the historically safe Dem seat will remain so, while the swing seats will be a bloodbath. By the way, all of in the GOP held seats, the generic is the reverse of the base Dem seats — 52% GOP/32% Dem. Very few, if any, Republican incumbents will be defeated.
Likewise, President Obama’s numbers with likely voters are similar to the national average — 46% approve/51% disapprove. However, in the Swing Democratic Incumbent Seats. he has a much worse 40% approve/57% disapprove. (Keep in mind, many of these Swing Seats are held by Democrats despite the fact that John McCain either won the district in 2008, or, even if losing, outperformed his national result.)