Over the last few election cycles, the typical post-convention bounce in the polls has been steadily decreasing — but this year’s conventions seem to be bucking that trend, at least for the Democrats. Nate Silver, the best poll analyst in the business, notes a significant bounce in all four major tracking polls.
On Friday, we began to see reasonably clear signs that President Obama would receive some kind of bounce in the polls from the Democratic convention.
Mr. Obama had another strong day in the polls on Saturday, making further gains in each of four national tracking polls. The question now is not whether Mr. Obama will get a bounce in the polls, but how substantial it will be.
Some of the data, in fact, suggests that the conventions may have changed the composition of the race, making Mr. Obama a reasonably clear favorite as we enter the stretch run of the campaign.
And these are daily tracking polls, which roll over the results of several days, which means, as Silver notes, that these numbers will probably go up further in the next few days. A little simple math based on the number of days that are rolled over suggests that the actual post-Wednesday bounce (after Clinton’s speech) is actually about 8 points. Here’s where Silver had the race as of Sunday afternoon: