Energized voters, in three crucial primaries, keep upending expectations.
Something extraordinary has happened on the way to George W. Bush's march to the Republican presidential nomination.
An epic political battle has erupted, an explosion of public sentiment that is reverberating beyond Republican Party halls into the heart of America's political system.
By winning the Republican primary in Michigan - again jerking momentum from Governor Bush, the favorite of the GOP establishment - John McCain has shown that his reformist insurgency is for real.
By no means, however, does it prove the Arizona senator is now poised to win his party's nomination. To the contrary, the challenge ahead may yet be insurmountable (see story below).
Still, even in states he has lost, including South Carolina last Saturday, McCain has achieved something akin to what independent Ross Perot did in 1992: a burst of interest in politics by a disaffected public that has, with the exception of 1992, voted in steadily declining numbers for decades.
So far, in the three most important early-primary states where Bush and McCain have competed head-to-head - New Hampshire, South Carolina, and Michigan - twice as many voters have turned out than did in those primaries four years ago.
The question is whether the Republican Party will ultimately incorporate this vast, available reservoir of public demand for reform, and perhaps build a new governing coalition, or stick to its current don't-rock-the-boat formula.
McCain supporters are now urging him to appeal to his own party's voters. In his victory speech Tuesday night, McCain signaled that he understands the task ahead. "We are reformers, Republican reformers who can make our party bigger and change politics in this country for generations," he said. "Don't fear this campaign, my fellow Republicans. Join it."
The concern for Republican regulars is that McCain voters come with a large price tag: a demand for changes in the campaign-finance system intended to reduce the influence - read, money - of "special interests" in American politics.
And as both major parties know well, money is the mother's milk of politics.
Observers see parallels between the insurgencies of McCain in 2000, Mr. Perot in '92, and more recently, Jesse Ventura, the third-party candidate who won the Minnesota governorship in 1998 using the same tell-it-like-it-is, outsider message.
But in 2000, the McCain phenomenon is fueled by a new strain of voter disgust, says Jack Pitney, a political analyst at Claremont-McKenna College in Claremont, Calif.