"The status quo," he said, "is not on the ballot."

But as the Republican presidential candidate is fully aware, the status quo always is on the ballot in a presidential election.

And this year, the increasingly grim economic state of the union is dragging McCain down - and boosting the electoral fortunes of Democrat Barack Obama.

In the broad sense, this is a pretty simple election and has been since the primaries ended.

It's all about the push and pull between two basic forces.

One is the desire of a big chunk of the electorate to bring change to Washington and throw out the Republicans for having brought America eight years of President Bush. The disturbing state of the economy has intensified that desire like nothing else.

The other is the uneasiness felt by millions of voters about Obama himself - his background, his associations, his record, and his level of experience in Washington.

In trying to exploit or mitigate those two forces, the two campaigns have pursued strategies that have been straightforward and obvious.

For Obama, the goal has been to link McCain to the unpopular incumbent as much as possible, to remind voters of all that has gone wrong - which hasn't been hard lately - and to offer reassurances that the Democratic nominee, despite his unusual name, truly is part of the American mainstream.

Hence, the current Obama commercial in which the candidate recalls being a child in Hawaii and going with his grandfather, a World War II veteran, to attend a flag-waving ceremony for astronauts whose space capsule had just been plucked out of the Pacific Ocean.

For McCain, the imperative has been to assert his independence from Bush on the economy and other issues, to talk about his own history as a maverick, and to feed the doubts about Obama's suitability to lead the nation in troubled times.

Hence, the McCain ad now on the air that highlights Obama's connections to William Ayers, the former leader of the Weather Underground, a violent, radical organization responsible for a number of bombings in the 1960s and 1970s.

It's no stretch to say that virtually everything that has happened since Obama wrapped up his party's nomination in June can be explained in terms of those two underlying factors.

During the summer, the McCain campaign gained ground by feeding the doubts about Obama through a series of commercials done after Obama's European trip.

The ads called him "the world's biggest celebrity" and made reference to Britney Spears and Paris Hilton. The implication: no substance behind the sizzle.

Obama rallied with a strong Democratic convention, tying McCain to Bush by hammering home the point that McCain had voted with the administration 90 percent of the time since 2001.

Then, McCain chose Alaska Gov. Sarah Palin as his running mate. Her presence on the ticket countered the Democrats' argument that McCain was seeking a third Bush term; Palin didn't look or sound like more of the same.

Since then, though, the balance has shifted yet again.

In the debates, if the polls are to be believed, Obama has struck many voters as calm, solid and reassuring, not the "too risky" alternative described by McCain.

And the economic crisis has reminded voters, rightly or wrongly, why they wanted to throw the Republicans out of the White House in the first place.

Much has been made of how the two candidates have handled the Wall Street mess so far. But the polls indicate that the facts of the meltdown itself, and the financial setbacks millions of Americans have suffered in the last few weeks, have done most of the damage to McCain.

To counter, the McCain campaign is again trying to play to the doubts about Obama.

It has escalated its attack on Obama's past and his character, doing much of it via Ayers - who hosted a fund-raiser for Obama during his first campaign in the mid-1990s and with whom the Illinois senator served on the boards of two nonprofits.

"Who is the real Barack Obama?" McCain asked at rally after rally last week.

Over the weekend, the Republican nominee toned down his rhetoric after an incident at a town-hall meeting in Minnesota that clearly bothered him. There, he got booed for calling Obama "a person that you do not have to be scared of as president of the United States."

Obama says the discussion of his past associations is an attempt to distract voters from the economic crisis and the role of Republican policies in making it happen.

"The fact that Sen. McCain wants to make this the centerpiece of his campaign is pretty remarkable," Obama told radio host Michael Smerconish of WPHT-AM (1210) last week.

At the moment, the impulse to blame the Republicans is overwhelming the worries that remain about Obama, his character or his policies, giving him a lead averaging 7 points in national polls.

There are 22 days left for the balance to shift once more.