The unspoken truth is that the Clinton machine is not being battle-tested at all by the Democratic primary process. When Mrs. Clinton accused John Edwards of “throwing mud” and “personally” attacking her in a sharp policy exchange in one debate, the press didn’t challenge the absurd hyperbole of her claim. In reality, neither Mr. Edwards nor any other Democratic competitor will ever hit her with the real, personal mud being stockpiled by the right. But if she’s getting a bye now, she will not from the Republican standard-bearer, whoever he may be. Clinton-bashing is the last shared article of faith (and last area of indisputable G.O.P. competence) that could yet unite the fractured and dispirited conservative electorate.

The Republicans know this and are so psychologically invested in refighting the Clinton wars that they’re giddy. Karl Rove’s first column for Newsweek last week, “How to Beat Hillary (Next) November,” proceeded from the premise that her nomination was a done deal. In the G.O.P. debates through last Thursday, the candidates mentioned the Clintons some 65 times. Barack Obama’s name has not been said once.

But much like the Clinton campaign itself, the Republicans have fallen into a trap by continuing to cling to the Hillary-is-inevitable trope. They have not allowed themselves to think the unthinkable — that they might need a Plan B to go up against a candidate who is not she. It’s far from clear that they would remotely know how to construct a Plan B to counter Mr. Obama. The repeated attempts to fan “rumors” that he is a madrassa-indoctrinated Muslim — whether on Fox News or in The Washington Post, where they resurfaced scurrilously on the front page on Thursday — are too demonstrably false to survive endless reruns even in the Swift-boating era.

Part of the Republicans’ difficulty in countering Mr. Obama, should they have to, is their own cynical racial politics. For the most part, race has been the dog that hasn’t barked in this campaign despite the (largely) white press’s endless fretting about whether the Illinois senator is too white for black voters and too black for white voters. Most Americans aren’t racist, most Republicans included. (Those who are won’t vote for the Democratic presidential candidate even if it’s not Mr. Obama.) But the G.O.P., by its own doing, is nonetheless saddled with a history that most recently includes “macaca” and Katrina, Mr. Bush’s appearance at Bob Jones University in 2000 and the nonexistent black population of its Congressional delegation.

Image Credit... Barry Blitt

As the Republican leadership knows, this record is an albatross, driving away not just black voters but crucial white swing voters, too. Ken Mehlman, the former G.O.P. chairman, and Mr. Rove, as recently as in that Newsweek column, have implored their party to reach out to minorities. So have Newt Gingrich and Jack Kemp. But not even conservative leaders of this stature could persuade their party’s top 2008 presidential contenders to show up for a September debate moderated by Tavis Smiley for PBS at the historically black Morgan State University.

It’s not because those no-shows are racists; it’s because they are defensive and out of touch. With the notable exception of Mike Huckabee, most of the party’s candidates have barricaded themselves from African-Americans for so long that they don’t know how to speak to or about them. As sure-footed as these Republicans are in attacking the Clintons and Streisand — or in exchanging fire with Al Sharpton and hip-hop moguls — they are strangers to the mainstream multiracial and multicultural America exemplified by an Obama or an Oprah.