SOUTH BEND, INDIANA Armchair advisers have told Barack Obama that he has to get down and dirty. They warn the Illinois senator that Hillary Clinton is pummelling him, accusing him of lacking experience, of being nothing but talk, of being elitist and out of touch.
He has to fight back, they say, go negative, remind voters of Ms. Clinton's pockmarked past, of her ruthlessness, of her many fabrications.
He can't do it. Philip Jerov won't let him.
Mr. Jerov is one of at least 15,000 people, almost all of them young, who filled the Dean Dome in Chapel Hill, N.C., earlier this week. They waited up to three hours, because Mr. Obama didn't get there till after 10 p.m. And when he finally arrived, they went crazy. It actually hurt the ears.
"I'm a really big supporter of what he believes in," Mr. Jerov explained, above the noise. "I want to see something huge happen to this country."
He is one of a legion, and he represents the most extraordinary phenomenon of this election year. Millions of young Americans have sloughed off their apathy and registered to vote for a single reason: They believe in Barack Obama.
"The energy was always there," said Erik Ose, 37, a fervent Obama supporter. "It was waiting. People were waiting for a leader who could set off the spark."
More than 165,000 people registered to vote in the North Carolina primary in the first three months of this year, three times the usual number. More than one million new Democrats registered to vote in the last seven states to hold primaries. And a great many of them are young Obamaphiles.
They power the hope that this campaign, this candidate, finally, truly could transform U.S. politics. But there are problems.
First, there aren't enough of them to counter the dominating power of the middle-aged masses who still control the political process. This is especially true in such midwestern states as Indiana, divided between industrial cities and farming communities, where Mr. Obama focused his attention yesterday before smaller gatherings of older voters.
Second, they tie Barack Obama's hands. He has promised these youthful idealists a new kind of politics, freed from the sullying taint of lobbyists and special interests, committed to major reforms in health care, the environment and education and dedicated to abandoning the war in Iraq and restoring America's moral centre.
Ms. Clinton has promised much the same. But she has no illusions about her ability to galvanize the nation. She is an old pol, who has sinned and been sinned against, who expects no quarter and who gives none, and who is grimly pursuing the essential political task of tearing down her opponent, of making him even less appealing than she is herself to much of the nation.
And Mr. Obama can't fight back. He cannot reciprocate her attacks, because he would be reverting to the very politics he has repudiated, the politics that has turned an entire generation off politics. He would risk losing Philip Jerov and Erik Ose and the millions of others whose youthful enthusiasm fire his campaign.
As things got unpleasant, in the days before the Texas, Ohio and Pennsylvania primaries, the campaign attempted a two-track approach. Mr. Obama kept to the high road, while his advisers in conference calls and e-mails dissed Ms. Clinton, accusing her of hypocrisy, mendacity, race-baiting.
But as Mr. Obama now tells people at rallies, he realized that all the name calling and high elbows were dragging his campaign down, detracting from his core message.
"Sometimes we've been hitting back in ways that aren't true to what our campaign is about," he told a crowd in Winston-Salem. "I've told my staff we have to guard against this."
And it is true that in recent days the back-channel attacks on the Clinton campaign from the Obama campaign have considerably diminished. Even at the worst, just before the Pennsylvania primary, his attack ads were never remotely as severe as hers. And in his campaign speeches he refers to Hillary Clinton as "running a terrific campaign," and refers to John McCain as "a genuine hero who is worthy of our respect," before trashing their economic platforms.
So Mr. Obama must run a principled campaign, even though other approaches might offer a surer route to victory. If he didn't, what would Tueo Yakah say?
"He gives us hope," explained Mr. Yakah, 24, after one rally, "and I know hope is overrated. But we need to believe that American dream is still possible. And that gets to me."
How can you go neg, when the young believe in you like that?
Youth and innocence v age and guile
As in past contests, Barack Obama has the support of North Carolina's under-35 set, and Hillary Clinton has the edge with the over-50 crowd.
VOTERS UNDER AGE 35
Support Barack Obama: 63%
Support Hillary Clinton: 26%
Unknown /undecided: 11%
VOTERS OVER AGE 50
Support Barack Obama: 45%
Support Hillary Clinton: 47%
Unknown /undecided: 8%
SOURCE: MASON-DIXON POLLING & RESEARCH INC.







