Dial "Z" for poll numbers

I’m allergic to math, but even I can understand why Barack Obama’s eight-point lead in the Zogby tracking poll is bigger than it looks.

Zogby has consistently had John McCain doing better than in many other polls. As Nate Silver explains, it’s because Zogby weights party affiliation based on exit polls from the previous election.

So if the electorate is more Democratic today than it was in 2004 — and it is, by quite a bit — then Obama’s lead is actually understated by Zogby. That is, if the tracking poll is accurate in the first place, which is always a question worth asking.

Moving on up

Tracking polls are notoriously unreliable, but the Gallup trend is clear:

• Aug. 23-25: McCain, 46 percent; Obama, 44 percent. Gallup’s take: “It’s official: Barack Obama has received no bounce in voter support out of his selection of Sen. Joe Biden to be his vice presidential running mate.”
• Aug. 24-26: Obama, 45 percent; McCain, 44 percent. Gallup’s take: “No major change in structure of race, though Obama is doing slightly better.”
• Aug. 25-27: Obama, 48 percent; McCain, 42 percent. Gallup’s take: “Democratic candidate gains in Monday through Wednesday interviewing.”

If these numbers are right, then it shows that all the media’s hyperventilating about the convention’s not being attack-oriented enough and the Clintons’ stealing the spotlight from Obama is bunk.

The latest figures don’t even capture voter reaction to Bill Clinton’s, John Kerry’s, and Joe Biden’s speeches, not to mention Obama’s cameo at the end of the night. And Gallup’s numbers won’t include Obama’s own speech until Saturday.

What does this mean? It looks like Obama is going to receive a normal convention bounce. And unless McCain and the Republicans utterly blow it next week, we’ll be back to a tied race when both conventions are over.

We’d all be better off watching C-SPAN.