"
Some notes and caveats…
As always, this EV history is viewed through state polls only, using Electoral College mechanisms. Therefore it is most sensitive to swing-state changes. In practice, changes in this index resemble changes in national polls. However, since the state polls sample more voters, the Meta-analysis has considerably less noise.
The horizontal axis reports the date that polls were released, and therefore when they entered the Meta-analysis. This accounts for the 2-3 day delay for a news event to exert its effect. I have color-coded the events for clarity.
The following events appear to be notable: the Bain Capital/tax return attacks, the Ryan VP pick, the Todd Akin “legitimate-rape” comment, and the last day of the Republican National Convention.
Some notes:
Bain Capital/tax returns. As I noted
at the time, this attack appeared to be very effective. I note that July 13th, which is nearby, was when President Obama made the “you didn’t build that” remark. I think we can safely discard
the hypothesis that the remark was a major, immediate help to Romney.
The Ryan VP pick. The pick of Paul Ryan on the GOP ticket led to major media saturation, and positive attention for Romney/Ryan. This drowned out other stories. As I pointed out at the time, the political media seems to be unable to cover more than one story at a time. This could account for the large, sudden shift.
Todd Akin. However, the Ryan bounce lasted
exactly one news cycle (i.e. one week). Todd Akin’s remark that “legitimate” rape victims don’t get pregnant may have hurt Romney…or maybe it just reset the media’s mindless attention.
The negative GOP bounce. As I stated before, the GOP convention was of no help to them in the Electoral College. Indeed,
it appears that the race shifted towards President Obama by 6-15 EV, or about 1.0% of Popular Vote Meta-Margin. From an analytical perspective, a negative bounce is quite remarkable. Such an event might have been missed in past years because national polls don’t have the best resolution.
The natural question arises: why would the Republicans be hurt by their own convention? Two answers come to mind.
(1) The Ryan-VP bounce effectively used up whatever room there was for a bounce. This year, opinion seems to be fluctuating in a very narrow range: Obama up by 1.0-5.0%. Maybe there was no room for improvement.
(2) The GOP convention was not particularly inspiring. Indeed, the most notable event was Clint Eastwood’s empty-chair routine, which overshadowed Romney’s acceptance speech.
And now we wait for the post-DNC bounce. I wrote the other day that given the narrow band of opinion movement, I will be surprised to see the bounce to go above 5.0% in Meta-margin or 330 EV. On the other hand, it was a very strong convention. The test will come in the numbers."
http://election.princeton.edu/2012/09/07/the-gop-convention-negative-bounce-a-final-look/