Now that the last scrap of confetti has been swept from the convention floors, Americans know what each major party promises in the presidential campaign.

Change.

It's surely a natural line for the Democrats, with Republican George W. Bush's two-term lease on the White House about to expire in a fit of unpopularity. Barack Obama gives the theme an extra twist, suggesting that he'd fashion -- or so he hopes -- a post-partisan Washington, breaking the mold of party-line division and tackling problems that stymie conventional politics.

And John McCain signaled Thursday in St. Paul, Minn., that he refuses to cede the field of change to Democrats. He too is taking change as his mantra.

It's an audacious stroke -- at once trying steal Obama's thunder and distancing the GOP candidate from the economic record of an unpopular president of his own party. And like Obama, McCain would seek to end "partisan rancor."

The thought is appealing. Is it plausible?

Accepting the presidential nomination before a convention still dazzled by Sarah Palin's speech the night before, the former Vietnam War POW and four-term Arizona senator cited a record of reaching across the aisle in Congress. Speakers dubbed McCain a reformer, and a "maverick." He proclaimed that as president he'd work just for "you" -- the public. He also offered the slogan "Country First," as an antidote to "me first" Washington thinking.

Otherwise the proud, wounded warrior -- tortured in a Hanoi prison -- located his policies in a traditional Republican framework. Lower taxes. Smaller government. Strong defense. Leadership.

It's a familiar package, but one that has produced many happy returns on Election Day. It will help Republicans give Obama a run for all the money he's raised. A convention, though, is intended to be an exercise in confidence-boosting. What's left when the glow fades?

The national economy is generally dismal: Unemployment has reached 6.1 percent, the budget deficit is $400 billion-plus and rising, and the stock market -- increasingly key to Americans' futures -- continues to disappoint. McCain offers few specifics on how he'd turn things around. His plans are mostly more of the same. Although fighting waste -- such as the earmarks Alaska enjoys? -- is admirable, it's hardly enough.

And while conservatives are on board with the maverick for now, a genuine party-bucker might be uncomfortable. Would the faithful favor bipartisan moves such as McCain's support for comprehensive immigration reform? Another McCain-Feingold campaign finance act?

If not, party-line government means more partisan rancor -- a point that applies to Obama's hopes, too. Most likely, a President McCain would be hard-pressed to make conciliatory moves, because if anything his party has shifted right. In a culture-wars revival, GOP speakers bashed "Eastern elites" and the news media. Delegates reduced energy policy to a chant of "Drill, baby, drill" -- implying no sacrifice, no real change.

Despite the graceful notes Obama and McCain struck about each other, and all the talk of change and hope, Americans could well face another rancorous campaign and another close election that pivots on negative ads in a few swing states. We can only hope that, at least, will change.

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