Republican presidential candidate John McCain yesterday came to the National Constitution Center, the site of Democrat Barack Obama's historic speech on race, to promise a scrappy fight for Pennsylvania's 21 electoral votes.

"We're going to go to the small towns in Pennsylvania, and I'm going to tell 'em, I don't agree with Senator Obama that they cling to their religion and the Constitution because they're bitter," the Arizona senator said, referring to Obama's widely publicized gaffe about bitter Pennsylvanians clinging to guns and religion.

McCain spoke briefly to the crowd of more than 500 and took questions on Iraq, taxes, the economy, education and health care, demonstrating why he favors the town-hall format.

He seemed relaxed and sure-footed, offering questioners a microphone for follow-up questions if they wanted.

McCain spoke only hours after generating controversy in an appearance on NBC's "Today Show." Asked whether he could estimate a time for withdrawing American troops from Iraq, McCain said, "No, but that's not too important."

McCain has said that he would tolerate a long-term military presence in Iraq as long as American casualties are ended, but the remark brought a torrent of criticism from Democrats and a defense by Connecticut U.S. Sen. Joe Lieberman, an independent who supports McCain.

"People are sick and tired of this kind of campaigning that's going on," McCain said at the town meeting, "the sound bites, the spin room, the media personalities that overshadow the candidates with the 'gotcha' questions."

McCain repeated his call for Obama to meet him in a series of town-hall meetings even before the Democratic convention.

McCain talked about the importance of winning in Iraq, calling Islamic extremism "a transcendent evil." He promised to "lead the nation on a mission which will eliminate, over time, our dependence on foreign oil."

He defended the Bush tax cuts, saying that controlling government spending is the key to controlling the deficit. And he spoke in general terms about health- care reform, warning that Obama "will lead to the government taking over the health-care system."

While it was clear that most in attendance were McCain supporters, spokesman Paul Lindsay said that crowds for his town-hall meetings are never screened for partisan loyalty.

As if to prove the point, the first question was whether McCain would work to advance an HIV bill now blocked in the Senate by Oklahoma Republican Tom Coburn.

"I'll be glad to assist," McCain responded. "I'm sorry to tell you I'm not that familiar with the process of this legislation."

Jennifer Cohn, an HIV physician who attended the event, was disappointed with the answer.

"Global HIV remains a major issue in our foreign policy as well as our domestic issues, and if that continues to be a weak spot of his, I'm going to wonder about his abilities in handling foreign policy," Cohn said.

While McCain is certain to lose Philadelphia to Obama, campaign events here generate media coverage that reaches suburban voters, a key constituency for the GOP candidate.

"He'll get here every chance he gets," said attorney Charles Kopp, a key McCain fundraiser. "He thinks he can win [Pennsylvania], so he has to put it in play."

After the meeting, McCain had lunch at the Union League with about 100 Catholic supporters. *