Call it the "Tale of Two McCains."

If you buy the central argument of Barack Obama campaign--at least when it comes to his Republican rival--John McCain suffers from something like split-personality disorder. The McCain of the past, says Obama, "can... legitimately tout moments of independence from his party." This is the "maverick" Arizona senator famous for his GOP-defying positions on "earmark reform and climate change" as well as immigration, torture, nuclear proliferation and campaign finance. According to Obama, though, this McCain is history. "Something’s certainly changed about John McCain," he says. Instead, the new and unimproved McCain is nothing more than a George W. Bush clone--a man "determined to carry out a third Bush term," "no matter what the costs, no matter what the consequences." Or so the Democratic nominee constantly insists. Obama's online fans have even given this McCain a cute little nickname: McSame.

There is a shred of truth in Obama's not-so-complimentary attack. In the wake of his 2000 loss to Bush, McCain drifted rightward as he positioned himself for a second presidential run. In the 107th Congress (2000-2002), he ranked as the 46th most conservative senator, according to voteview.com--a moderate record. By the 109th, he had become the second most conservative. And there's no denying that McCain reversed course on Bush's tax cuts, which he opposed in 2001--"I cannot in good conscience support a tax cut in which so many of the benefits go to the most fortunate among us at the expense of middle-class Americans who need tax relief," he said at the time--but now wants to make permanent. That shift (along with the fact that McCain has always been an orthodox conservative on social and economic issues) has provided Obama, who's eager to tie his Republican rival to an unpopular president and claim the mantle of change for himself, with the fodder necessary for a "McCain Is Bush" onslaught.

The only problem? Obama's leap from "McCain agrees with Bush more now" to "McCain will govern exactly like Bush" is pretty misleading. Presidential elections are about how the present will affect the future, not how it differs from the past. Which means that the most consequential question confronting voters in an election year is how a candidate will govern tomorrow, as president. And as any objective observer will admit, there's simply no way McCain would ever "carry out a third Bush term."

Fact is, he couldn't--even if he wanted to. According to the Cook Political Report, the Democratic Party is poised to pick up 10 to 20 seats in the House of Representatives and four to seven seats in the Senate. At best, that would give the Dems voting majorities of 77 and 16, respectively--margins much larger than any enjoyed by the GOP during Bush's tenure in the White House. So just as running for the Republican nomination has forced candidate McCain to emphasize his conservative bona fides, facing off against a heavily Democratic Congress would force President McCain to make compromises--if, that is, he hoped to accomplish anything in office.

At this point, McCain would undoubtedly deviate from Bush's divide-and-conquer playbook. Whereas Bush and Co. arrived in Washington, D.C. "believing that the intensity of Republican support was more important than the breadth of his appeal"--Karl Rove, for example, advocated a "50 percent plus one" approach to governing--McCain has a long record of working with Democrats when necessary. Without a majority, it would be necessary. As president, then, McCain would likely do what he has plenty of practice doing in the past--partnering with Dems on immigration (McCain-Kennedy), campaign finance (McCain-Feingold), climate change (McCain-Lieberman) and even education--while skipping the stuff he's never been particularly enthusiastic about, like pushing for conservative social policies to please right-wing Republicans. On Iraq, the economy and even Supreme Court justices, he would have to find common ground or risk gridlock. As president, McCain would have a pretty clear-cut choice: either a) bend or b) get nothing done. Not much room for Bush-like behavior.

In any case, McCain would have little incentive to kowtow to conservatives. Unlike Bush, he'll win in November in spite of the right--not because of it--and arrive in the Oval Office owing moderate Independents and crossover Democrats more than he'll owe Republican extremists. What's more, he's unlikely to design every policy position for maximum political advantage--a hallmark of the Bush regime--for the simple reason that this election may be his last. As the Atlantic's Marc Ambinder reported earlier this month, "when he formally announced his presidential candidacy last year, Sen. John McCain was inches away from making an unprecedented pledge: if he were elected, he would serve only one term as president." He didn't go through with it, of course, but the implication--that getting reelected is less important getting the job done--still holds truer for him than most. Without another election looming on the horizon, pissing off your party is no longer the worst thing in the world.

Yes, McCain is a Republican. Yes, he--like Bush--has Republican positions. And yes, you should vote against him if you disagree with the Republican Party on the issues. My only point here is that McCain, based on his bipartisan past, is probably one of the Republicans least likely to govern like Bush--and thus least deserving of the inevitable "Bush III" label. None of this is to say that McCain would be a perfect president, or even a good one. I'll let the voters decide that.  Maybe you think he's too old. Maybe you think he's too conservative. Maybe you think he's squandered his honor for political gain. Maybe you just like Obama better. Any reason is fine, as long, that is, as the crucial comparison is between Obama and McCain--their policies, their personalities and the problems they'll face as president--and not between Obama and Bush. Because even though 43 has done some preposterous things during his time in the White House, he's not defying the Twenty-Second Amendment to run for a third term--despite what Obama says.