On Monday George W. Bush moved a step closer to the presidency, thanks to Patrick J. Buchanan. Buchanan, the presidential candidate most likely to espouse federal subsidies for off-Broadway productions of "Springtime for Hitler," bolted the Republican Party for the Reform Party, whose motto might be "United, We're Fruitcakes." In his departure, as is his tedious habit, Buchanan declared war:

"Let me say to the money boys and the Beltway elites who think that, at long last, they have pulled up their drawbridge and locked us out forever--you don't know this peasant army," Buchanan said. "We have not yet begun to fight."

Oh yes, you have, Pat, my boy. Begun, finished and lost. Currently, Buchanan is pulling about 9 percent in the polls, 6 percent from the Republican fringe and 3 percent from the Democratic. This will be his high-water mark.

It is not at all certain that Buchanan will receive the Reform Party nomination, as he may face a challenge from Donald Trump, who suffers from the delusion that someone in America can stand him. If Buchanan does get the nod and runs in the general election, he will be a blip at the polls. Some candidates wear well, some do not. A candidate who wishes the voters to understand why World War II was The Bad War is an example of the latter.

For this reason alone, the conventional analysis that Buchanan could cost Bush a close election is wrong. Buchanan is not going to move enough votes to make that kind of difference.

More important, Buchanan's decision to go off the political grid will strip the Democrats of the one potentially potent weapon they had to wield against Bush. This is the false charge that Bush represents a Republican Party that has become the captive of isolationist extremists.

Exhibit A in this argument is the Senate defeat of the badly flawed Comprehensive Test Ban Treaty. Never mind that the White House ensured this defeat, by design or ineptitude, in allowing an avoidable vote; Clinton nevertheless seized upon his defeat to mount a furious and remarkably mendacious assault on Republicans as foreign policy cave-dwellers whose very existence threatens world peace, national security and our children asleep in their beds.

A problem in this argument, as it pertains to the presidential election, is that the likely GOP candidate, Bush, is manifestly not any sort of isolationist, neo or paleo. To the degree that Bush cares about foreign affairs, which is not a lot, he is his father's son, a conventional Republican internationalist. He is a free-trader, a China-engager, a NATO-expander. He has chosen foreign policy advisers so comfortably establishmentarian that they might be invited onto the set of "The NewsHour with Jim Lehrer."

Still, as the Clinton-Gore war-roomers know well, mud sticks, and the charge could be made against Bush that he was at least soft on the isolationists, a fellow traveler. That charge could stand for only one reason: Bush had declined to join his rival John McCain in denouncing Buchanan's world war revisionism. But now Buchanan, a Republican no more, has freed Bush to smack him around, a liberty Bush promptly took. "Pat sees an America that should have stayed home while Hitler overran Europe and perpetrated the Holocaust," said the suddenly unmushy Bush. "Republicans are proud of America's role in defeating Nazi Germany."

The Republican Party is not isolationist. The Republican House of Representatives may be, but it is clear that the leaders of the House do not lead the party; actually, they don't even lead the House. Indeed, the only nationally known Republican who strongly argues the isolationist case is none but Patrick J. Buchanan--and his appeal to Republican voters may be gauged by the fact that he won all of two primary contests in his last presidential run.

Now Buchanan is out of the GOP. The Democrats have lost their most important demon, the face of Republican isolationism. And the Republicans, George Bush especially, now may--indeed, must--define themselves in opposition to Buchananism. Buchanan will make sure of that. He will be the gift that keeps on giving; he will declare his proud crackpot's creed every day, and every day give Bush a chance to declare himself the anti-Pat.

"They call us isolationists," Buchanan said on Monday. "Well, if they mean I intend to isolate America from all the bloody, territorial, tribal and ethnic wars of the 21st century, I plead guilty." The only thing Buchanan has the power to isolate is himself. And in so doing, he has given Bush the greatest of gifts. Which, when you think about how much Buchanan and his new boss, Ross Perot, feel about the Bushes, is really rather sweet.

Michael Kelly is the editor in chief of National Journal.