The convention floor was abuzz all yesterday with the news of the CBS poll showing a dead tie (42-42) in the presidential race. And the poll, conducted through Wednesday, couldn't reflect the impact of John McCain's speech, or the full impact of Sarah Palin's late Wednesday night. It reflected opinions only after the Democrats' convention, Barack Obama's incredible speech, the Palin selection and the early, Gustav-depressed GOP gathering.

That augers ill for the Democrats. Tonight's polling could bring evidence that the Obama candidacy is in big trouble.

First, the GOP convention managed to disprove the central premise of the Democratic assault on McCain: that he is a clone of President Bush. The Republicans wisely marginalized Bush to a non-prime-time videotaped speech, and sprinkled disappearing dust on Dick Cheney.

The speeches, and the very fact of the Palin designation, repudiated Washington and focused on how McCain is an agent of change - this ticket is populist, reformist, anti-establishment, grass-roots and anti-corruption.

And McCain last night made the point plain: "Let me offer an advance warning to the old, big-spending, do-nothing, me-first-country-second Washington crowd: Change is coming."

If Bush were the nominee, this campaign wouldn't suffice to push voters away from Obama. But now that McCain has moved decisively away from the administration, Obama's lost much (at least) of his advantage on the issue of reform. Now other doubts about Obama could elect McCain.

The turning point was the designation of Palin and the personal attacks on her. By stirring up a storm, Democrats assured that Palin would speak to 37 million Americans - just a million fewer than watched Obama's acceptance speech.

Anecdotal evidence already suggests that women may have a gut reaction to the establishment's sexist assault on a woman candidate - and flock to McCain. They've seen him stake everything on this one big move of turning toward a woman - in direct contrast to Obama's deliberate decision not to name a woman.

They've seen the media and Democrats gang up on her and do their worst. And they've seen Palin stand up and stuff the challenge right back down the establishment's throat. All this may have created an entirely new dynamic in the race.

Now the Republicans must battle to underscore the threats this country faces, economically and internationally, and that we can't let an ingenue take over. They must capitalize on McCain's aggressive determination to bring reform to Washington and to emphasize Obama's inexperience and failure to grasp how to change Washington.

But it was McCain's gutsy selection of Palin that opened the door to victory.