Ways to get votes

There are two ways that popular opinion can change: Either an exogenous event can make a large number of people change their minds at once, or votes can randomly drift from one candidate to another for no obvious reason.

The "event" type is usually widely reported. For example, when the Jeremiah Wright story broke, the Obama-McCain spread swung about 4% towards McCain; or when Hillary Clinton dropped out, the Obama-McCain spread swung about 3% towards Obama.

The "drift" type is widely ignored by the media, which I can't fault them for. Inexplicable random drift over the course of a month-and-a-half doesn't make a compelling story. The only example in this cycle is that the Obama-McCain spread swung about 3-4% towards McCain, quite steadily from early July to mid-August.

At this point in the race, there is essentially no way that John McCain can catch up through mere random drift. The July/August drift was spectacular for McCain, as far as drift goes, but even if he improved at that rate of about 3%/month, McCain would still fall short in early November.

That means that McCain desperately needs a major event in his favor. He seems to be trying to generate a major event himself, such as the gimmick of pseudo-suspending his campaign last week. However, I think it's hard for a campaign to generate its own event -- witness the tiny blip that Obama's heralded international trip achieved. Maybe a big win in one of the next debates could do it, or a major international security incident. Or maybe Putin rearing his head in our airspace. I don't know what it could be, but McCain needs it to happen, or he will lose.

Key point: Unless some big happens, Obama will win.