What if Day One never comes?

What if you've spent your life preparing to be "Ready on Day One," but it never arrives?

Hillary Clinton may be about to find out.

By midnight's chime, her bid to become president of the United States, which once swaggered in an aura of inevitability, could be dead.

Even if she wrests enough delegates from today's primaries to stay alive, her hope for the Democratic nomination will depend on a long, wounding slog that would only damage her chances of beating John McCain in the fall.

The best argument against nominating her has always been that she's the only Democratic nominee who could unite the splintering, dispirited Republicans. She's their favorite common enemy.

Now, add this factor: To win her party's nod, she'll probably have to wield the kind of backroom muscle that will turn off the young, idealistic voters who've flocked to Barack Obama and who represent Democrats' best hope for a sweeping win.

How did it come to this?

If Obama today adds Texas and Ohio to his skein of primary wins, volumes will be written about the Clinton team's tactical and strategic errors.

Those mistakes flow from a core miscalculation: Clinton never grasped how weary America has become with her boomer generation - and the Clinton couple as its compelling but flawed avatars.

Just as Bill Clinton's election in 1992 was emblematic of the huge boomer cohort's belated coming of age, Hillary Clinton's troubles in 2008 speak to a national desire to shove this striving, self-absorbed, maddening crew off center stage.

As a prototypical boomer, Hillary Clinton could not see that. It's hard for boomers (and I'm very much one) to imagine a universe - political, cultural, economic - that doesn't revolve around them. She conveys a sense that she's special, entitled, destined to move forever on a rising arc.

That's why she never saw Obama coming, even long after he'd arrived.

Although Obama was born a few years before 1964, the boundary of the baby boom, he is essentially the first post-boomer national politician, refusing to be defined by the searing arguments of the 1960s. He doesn't just triangulate the culture wars. He supercedes them.

When he said in his thrilling 2004 convention speech, "We worship an awesome God in the blue states," it was the clarion of a new era.

The Clintons were the cleverest Democrats, and the best wonks, of the dying era. They maneuvered ably amid a landscape defined by Ronald Reagan's devastating critique of old-fashioned liberalism.

But now another ruling ideology crumbles under the weight of its sins: angry, blaming, antigovernment Big Conservatism. It is a new day, which Obama wants to seize. The Clintons just want to refight the old war. They don't grasp how retro, how "my parents' politics" this makes them seem to Americans under 30, for whom their '90s scandals were the backbeat of adolescence.

This is why Hillary Clinton's drumbeat about "experience," her mantra of Ready on Day One, has not worked as she expected. It's also why her warnings that Obama the Naïf will get chewed up by right-wing attack dogs have not hit home.

Experience can teach, but it can also scar. Hillary Clinton is the most unreasonably reviled politician of her era. (Sexism gives the vitriol against her a special bite.)

She thinks that makes her uniquely equipped. Instead, it might make her uniquely unable to see the opportunity Obama has seized. He promises a new style of politics to those feeling bruised by the "create-a-wasteland-and-call-it-victory" tactics of the attack ad, the scurrilous flyer, the 24/7 "war room."

She thinks Obama too idealistic; perhaps she's too scarred. The abuse she's taken has given her a fortress mentality: quick to find grievance, slow to admit error. She has many admirable traits, but the way she behaves under right-wing attack isn't one of them.

She repeats her "poor Barack, he doesn't know what he's in for" riff even as Obama shows that his new moves thwart the old ones. She doesn't seem to notice that the Republicans have nominated a candidate too classy to play Bush-Rove gutter politics.

Yes, the bloviating apparatchiks of the right-wing machine will go after Obama with their usual venom. He's shown that the way to counter such stuff is not to get mired in it, but to appeal instead to the better angels.

Obama can do a Ronald Reagan on the partisan dogs. When they come after him with the Hussein gibes and other nonsense, he can turn to the public with a knowing smile and say, "There they go again." People will cheer.

What Americans seek is Day One of a new era, not of a new season of