The post-Foley Folly polls find an upturn in the Democratic margin in the generic Congressional ballot. Prior to the Foley developments, Democrats held a 10.6 point lead in the polls. (This is the Dem percent minus the Rep percent.) That lead has now jumped to 12.8 points, the highest my trend estimate has reached in the 244 generic ballot polls taken this election cycle. This is all the more important because prior to the Foley Fiasco the trend had moved a bit down, then flattened (though still at or about 10.6, a very strong margin even then.) Whatever possible gains Republicans were beginning to make have now been wiped out.
One important concern is that CNN and Gallup produce extraordinarily high values on the generic ballot in this poll. (Remember, these are now done independently-- CNN uses Opinion Research Corporation for it's polling, while Gallup now polls for USAToday only since the dissolution of the old CNN/USAToday/Gallup partnership.) These values of over 20 points are simply implausible given the rest of the data over the past two years, and the other data from the past two weeks. Could it be that my trend estimate is being unduly influenced by these two absurd results?
No. If I exclude the latest CNN/ORC and Gallup/USAToday polls, the trend estimate is a Democratic advantage of +12.4 points, rather than the 12.8 points if these two are included. That small change in trend would still be the highest Democratic margin of the past two years, and when plotted the line without these polls is visually all but indistinguishable from the blue trend line in the figure.
And so we are back to the key question: how much will this huge (compared to elections since 1994) Democratic lead translate into seats? Will we see movement in polls for individual House races move as well? Stay tuned.
Note: This entry is cross-posted at Political Arithmetik. Typo corrected.