Wednesday, September 10, 2008

Post Convention Bounce in the States

The McCain campaign has gained significant support in national polling since the end of the Republican Convention, but what about the state polls? Has the shift also been reflected there?

State pollsters appeared to go on vacation for the conventions, with very little new polls during the two weeks of conventions (and the week before). Now the pollsters are back, tanned and rested and ready to go. We've added 17 new state polls since the RNC ended, and while we'd love to see more, it is enough to get started with some analysis.

The chart above shows the national trend in blue and the trend based on those states with post-convention polls in purple. Over the course of the year, the two trends have followed each other rather well with some small differences in details but qualitatively similar patterns of up and down movement.

Now in the post-RNC period, the states with new polls match the national polls quite closely, both giving estimates of about a one point McCain lead, with the states maybe a shade less than that.

This post-convention bounce may or may not last, but at the moment the evidence is that it is moving across the states (and these are mostly competitive states) at about the same rate as it is for the national polls.

The state polls show no positive DNC upward bounce, but that's because there were practically no new polls during that period, so don't jump to that conclusion. It is an artifact of no polls.

States for which we have new polls are Colorado, Florida, Maryland, Michigan, Montana, New Jersey, North Carolina, Ohio, Oklahoma, Pennsylvania, Virginia, Washington and Wisconsin.