Reviewing 538's House Outlook

I largely agree with Nate Silver's weekend outlook for the House.   But lets take a look at this portion a little more in depth:

FiveThirtyEight's projection for the U.S. House shows little change from last week. Republicans are given a 73 percent chance of taking over the House, up incrementally from 72 percent last week. During an average simulation run, Republicans finished with 227 seats, up from 226 last week; this would suggest a net gain of 48 seats from the 179 they hold currently.

However, there is considerable uncertainty in the forecast because of the unusually large number of House seats now in play. A gain of as large as 70-80 seats is not completely out of the question if everything broke right for Republicans. Conversely, if Democrats managed to see a material rebound in their national standing over the final two weeks of the campaign, they could lose as few as 20-30 seats, as relatively few individual districts are certain pickups for Republicans.

In past weeks, we have written about the divergence between the various indicators that the model uses - for instance, the generic ballot, as compared against polls of individual districts. Increasingly, however, these metrics are falling into alignment.

Some generic ballot polls have shown incremental improvement in Democrats standing - although they still trail by roughly 6 points among likely voters on the generic ballot, according to our model's estimate. According to one commonly used formula, a Republican lead of 6 points on the generic ballot would translate into a gain of about 50 seats.

So in this scenerio what happens if the Congressional Generic is not plus 6 GOP but 1-3 points? Is that 10-25 seats?

As I wrote a few days ago I just dont think we can say conclusively that the Congressional Generic ballot is 6 percentage points.  There is mounting evidence that the Gallup generic, which came up so Republican of late, is simply flawed, and wildly skewing the aggregate generic number.  Discounting Gallup and the GOP leaning Fox and Rasmussen and the aggregrate generic gets down to low single digits, withing the margin of error.  Last week in the 5 polls taken not including Fox/Rasmussen the generic was actually tied.

In Nate's simulations, that would certainly have the Democrats keeping the House, and losing somewhere between 10-25 seats.  While Nate's model allows this possibility, I think we all have to look harder at whether the likelihood of this outcome has risen in recent weeks.  I think it has.

Update - The new AP poll which got a lot of play this weekend has the generic at 39/34 for the Democrats.