Sen. John McCain, the presumptive Republican nominee for president, said during a wide-ranging town-hall meeting Wednesday at the National Constitution Center that the "surge" of troops in Iraq is working, and he pledged to campaign hard to carry Pennsylvania.

"I know it has caused a tremendous amount of pain, but I believe . . . with this new strategy they are succeeding," McCain said, citing reduced violence in Iraq. He said his Democratic opponent, Sen. Barack Obama, "still believes it is not succeeding, despite the facts on the ground."

Pennsylvania is likely once again to be a presidential battleground, and McCain vowed to campaign hard in the state even though it has voted for the Democratic nominee in the last four elections. He made a particular point of welcoming supporters of Sen. Hillary Rodham Clinton, who won Pennsylvania in the April 22 Democratic primary but lost the nomination to Obama.

"We're going to go to the small towns of Pennsylvania, and I'm going to tell them that I don't agree with Sen. Obama that they cling to religion and the Constitution because they are bitter," McCain said, to cheers.

Obama ran into trouble in the runup to the Pennsylvania primary when remarks he made at a private fundraiser came to light. In them, he said that small-town state residents "cling" to guns and religion and fear of people different from them because of anger over their economic struggles.

McCain said Obama was wrong to propose increasing the capital-gains tax rate, among other levies, given the soft economy, and said the Democrat's health-care plan would lead to government control of the nation's health-care system. "We've seen that movie before," he said.

While he said he "respects and admires" Obama, McCain said they had significant philosophical and policy differences.

"As you know, one of the big attacks on me is that my administration would be President Bush's third term," McCain said. "Well, from what I've seen of Sen. Obama's proposals, (he] would be very akin to a second term for Jimmy Carter.

"In fact, from national security to taxation to increasing the role of government it would seem that Sen. Obama's dusting off the old policies of the '60s and '70s that have failed."