To hear some journalists tell it, Obama supporters can begin to relax: it'll be almost impossible for McCain to win this election.

I'm not seeing that, in the polls or anything else. This morning, Obama's ahead by 5.6 points in the RealClearPolitics average of major national polls. That hasn't changed much in the past week, even though polls say the public thinks Obama won Tuesday's debate.

Yes, Obama is ahead in some important battleground states, but by slim margins. Plenty of voters are still undecided. And the race problem makes those margins suspect.

So I continue to worry.

Worth reading, on a related subject: Chalmers Johnson's "Voting the Fate of the Nation," on The Nation's website. Johnson's topic is whether this election might result in "a period of reform and political realignment," similar to the periods following the election of Franklin Roosevelt and Richard Nixon.

Both candidates, Johnson notes, are promising change. "Bringing the opposition party to power, however, is not in itself likely to restore the American republic to good working order," writes Johnson. "It is almost inconceivable that any president could stand up to the overwhelming pressures of the military-industrial complex, as well as the extra-constitutional powers of the sixteen intelligence agencies that make up the US Intelligence Community, and the entrenched interests they represent."

For a president to stand up to that pressure and bring about significant change, we'll have to have a major realignment of voters. Democrats, says Johnson, will have to win the election "in smashing style." And it's not clear, he says, that that will happen.