She's going to keep coming. The Obama campaign can tout "the math." Pundits can insist she leave the race. Former liberal supporters can complain about her smash-mouth tactics. But Hillary Clinton is not going to relent.

The New Yorker compares her this week to a Hollywood cyborg or zombie. To make a current movie analogy, she's the Anton Chigurh of Democratic politics. As the creepy villain of the Oscar-winning "No Country for Old Men," the murderous Chigurh is an unstoppable force. If "No Country" is a movie about the inexorability of evil, the Democratic race could be about the inexorability of Hillary Clinton.

She's not electrifying on the stump, her campaign is dysfunctional, and -- truth be told -- she's not particularly experienced. What Hillary has is a shameless will to power, and a near lock on an old-school Democratic coalition built on working-class whites. That is enough for her to try to pry the nomination from Obama's hands one finger at a time.

When the Obama campaign and its supporters in the press say "the math" rules out Hillary, they mean that she will never catch Barack Obama in pledged delegates won through primaries and caucuses. He probably will continue to lead her by about 100 pledged delegates out of roughly 3,200 total. But nothing says that the leader in pledged delegates wins the nomination.

Both candidates will need superdelegates -- the 800 party poobahs free to vote for whomever they please -- to get to the magic number of 2,025 total delegates. "Math" obsessives assume that the superdelegates will go with whomever has the most pledged delegates. But why?

After Ohio and Texas, Hillary trails Obama in the overall popular vote by only 600,000 votes out of 25 million cast. If you count Florida and Michigan, which weren't contested, Hillary leads Obama slightly. Obama padded his pledged-delegate lead with overwhelming wins in caucuses that aren't as open and democratic as primaries. In the hybrid primary-caucus state of Texas, Hillary beat Obama by three points and 100,000 votes in a primary where 3 million people voted. But Obama will get more pledged delegates out of the state because he beat Hillary in a caucus where 100,000 people participated. And Obama is the candidate of people power?

The Washington Post talked to 80 superdelegates who said that if the race is basically a tie, they will support the candidate who matches up best against John McCain and will make the best president. That is an open question, subject to different answers based on ongoing developments.

It's time for Obama -- as the Hillary character said to the Obama character in the latest devastating sendup of Obama on "Saturday Night Live" -- to "man up." He can't throw the "kitchen sink" back at Hillary. Instead, he has to demonstrate his toughness by connecting with traditional Democrats on bread-and-butter issues, and by reacting to his newfound political adversity with aplomb (i.e., no whining about his press coverage becoming less worshipful).

When Hillary and Bill Clinton talk of Obama as Hillary's pick for vice president, they are targeting Obama's toughness. They surely believe that, faced with a Hillary who will go to the convention and spoil his nomination with a nasty floor fight if she has to, Obama will blink. That for the sake of his party and the cause of change, he'll take a unifying deal that puts him in the No. 2 slot.

Obama is trying to knock down the notion, but has yet to burn his ships behind him by ruling out running as VP in any circumstance. Unless he does, doubts will remain about whether he has the stomach for what Hillary will drag him through. Faced with the implacability of Anton Chigurh, after all, the "outmatched" sheriff in "No Country" retreats into retirement.

About this there can be no doubt: When Hillary said at the beginning of her campaign that she's "in it to win it," she meant it.