THE LAST PERSON BARACK OBAMA wants as his vice presidential running mate is Hillary Clinton. But could she, with key assistance from her husband, former President Bill Clinton, force her way onto an Obama ticket? The answer: don't bet on it.

Obama, once he locks up the Democratic presidential nomination, has numerous reasons for picking someone other than Clinton. The most important is that an Obama White House, with Clinton joined by Bill down the hall from the Oval Office, would be dysfunctional, a center of political intrigue, leaks, and rivalries. And there are legitimate doubts as to whether Clinton, with half the country regarding her unfavorably, would be his strongest partner in the fall campaign against Republican John McCain. A dream ticket? Not necessarily.

There is, however, a plausible strategy for getting her on the ticket, one suggested (though not advocated) by Democratic consultant and Fox News commentator Bob Beckel. Here it is: Bill Clinton would convince dozens of Obama-supporting superdelegates at the Democratic convention to vote for Hillary for veep, and joined with her delegates, they'd be a majority. Obama would have to accede. The vote for the vice presidential nomination, by the way, is separate from the vote for the presidential candidate.

What's wrong with this scheme? First, Hillary's argument for being on the ticket has a flaw. She often points out how well she's does in the popular vote in the primaries, especially in winning working class, Catholic, Hispanic, and women voters. But there's no reason to believe these folks are uniquely her voters. Many may have voted for her simply because they don't like Obama. Any rival of Obama in the Democratic primaries might have won their votes.

True, Clinton passes the first test for a vice presidential choice: she's a plausible president. But the second test is what one adds to the ticket. Does she guarantee an Obama victory in a critical state that he otherwise would lose? The answer is no. But either Governor Ted Strickland of Ohio or Ed Rendell of Pennsylvania would surely bring their battleground states if they run with Obama. And Senator Jim Webb of Virginia would add national security credentials and a populist economic message to the ticket. Clinton couldn't match that.

A bigger problem for the Clinton strategy is that Obama could thwart it by picking a running mate weeks before the Democratic convention. His anointed veep would campaign with Obama and thus be established as a member of the ticket well before the delegates gather in Denver in the last week of August. Would the delegates really be willing to embarrass Obama by making him drop his preferred running mate in favor of Clinton? Not likely.

The Hillary-for-veep strategy would have a better chance of success if it unfolded just as the primaries end on June 3. Bill Clinton, who is probably on a first-name basis with the vast majority the 800-plus superdelegates, would quickly line them up for his wife. Then, before Obama had decided on a running mate, the Clintons would present him with the fact that a majority of the delegates wanted his choice to be Hillary. That would create a dicey situation for Obama, but he'd still have to refuse.