The state-poll Meta-Analysis history reached an extreme yesterday, as I predicted. Today it jumped sharply upward. It will continue to follow national poll trends with a delay.

At a national level, the post-GOP convention bounce is definitively over. Nine polls give a median margin of Obama leading by 4.0 +/- 1.3 %. The transition away from a McCain lead coincided with the McCain and Palin television appearances and the Saturday Night Live takedown by Tina Fey.

The national polls used to calculate this were conducted Sep. 11-17. They were

• DailyKos/Research 2000 Tracking (D) – Obama +6%
• CBS – Obama +5%
• Quinnipiac – Obama +4%
• Diageo/Hotline Tracking – Obama +4%
• Gallup Daily Tracking – Obama +4%
• Ipsos/McClatchy – Tie
• Rasmussen Tracking – Tie
• Economist/YouGov – McCain +2%
• American Research Group – McCain +3%

In case of tracking polls the most recent available number was taken.

Two useful benchmarks for future reference will be the peak margins seen after each party’s convention. I view these as candidate high-water marks for each candidate. Obama’s largest lead was 6.5 +/- 1.3%. McCain’s largest lead was 2.0 +/- 1.2%.

I’m going to cut down on these national-poll updates. The original reason was to stay ahead of the lagging state polls. The next planned major event isn’t until the first debate next Friday night. That should be long enough for the EV estimator to catch up with events somewhat. It’s unclear to me where it’s headed now – probably somewhere above Obama 300 EV.