MALVERN, Pa. -- Sen. Barack Obama was preaching to the choir today during a speech at Great Valley High School in Chester County, where he spoke of plans to pay teachers more and reduce reliance on standardized testing and make college more affordable.

The diverse crowd of 1,000 -- including 300 teachers and students of voting age -- cheered for his education reform plans.

They also took to their feet at his mention of his position on the Iraq war.

"The person you want to answer the phone at 3 a.m. is the person who has read the intelligence reports and who is asking the tough questions about why we wanted to invade a country like Iraq that has had nothing to do with 9/11," the Illinois senator said during the town-hall style rally.

"I opposed the war in 2002, and I will end the war in 2009," he said, drawing them to their feet again.

Most students withheld their applause, though, when he responded to a question about plans to improve college affordability.

"Students have to be better consumers of higher education. If you talk to a lot of presidents of universities, they say, 'We've got to build a state-of-the-art gym with a gourmet cafeteria and get a big-screen TV in the student lounge because that's what students have come to expect,' " Mr. Obama said.

"Student fees and facilities have driven up costs a lot. When I was going to school, we knew the food was going to be bad and the gym didn't have all the state-of-the-art Nautilus equipment," he said. "You didn't expect first-class facilities because you were there to learn."

Other audience members grilled him on the health of the Social Security and relations with China.

Here's how Mr. Obama responded:

• Social security is not in crisis but change is needed to ensure future retirees will get as much benefit as they are expecting. He proposes to fix the problem by raising the cap on the amount of income subject to payroll tax. Currently, only the first $97,000 of income is taxed.

• The United States is undermining its own economic power by borrowing from China while allowing the Chinese to devalue American currency and to export sub-par steel and other goods here. "That's just not fair and it's not right and it's going to undermine our economic position over the long term," he said.

Mr. Obama heads to Bucks County next for a similar town-hall style meeting later today at Truman High School in Levittown.