The two candidates covered a variety of topics at the debate at Hofstra University in Hempstead, N.Y., including taxes, offshore oil drilling and health care.
Many of the debate-watching parties in the Democrat-heavy Bay Area consisted of Obama supporters, but fans of McCain were watching too and believe their candidate did well.
A local political expert today gave his take on how the debate went.
University of California, Berkeley assistant professor of political science David Karol, who specializes in American politics, said the debate was "very unlikely to make a difference" because Obama already had a "significant" lead prior to the debate.
"McCain needed for Obama to collapse and that didn't happen," Karol said. "Obama is way ahead now."
Karol said Obama "projects this kind of serenity" that makes him seem knowledgeable, which is important for those who don't know about each issue being debated.
"A lot of people who watch the debates can't necessarily follow all the ins and outs, so they just get a sense of, does this person seem competent? Do they have a presidential demeanor? Do they share my values?" Karol said.
However, Ryan Hatcher, executive director of the Alameda County Republican Party, said he and the other members of the group thought McCain came to the debate prepared, was on the offensive and that it was his best debate of the three.
"McCain did a great job of really cutting through some of Obama's rhetoric ... and pulled out some issues that really impact Americans that Obama just talks around," Hatcher said. "More than any other debate, McCain challenged Obama on the feasibility of his policies."
Hatcher added that he thought the debate was Obama's worst, because the senator "spent the entire time rehashing points and couldn't defend a lot of his stuff."
McCain speaks honestly, he said.
"He doesn't speak like a politician; he says things the way he actually sees them. And that's what people love about this guy," he said.
Karol, though, thinks McCain's demeanor may have hurt him.
"There are points where I think McCain had a stronger argument than Obama, but he's clearly kind of angry, and that doesn't come across well on television," Karol said.
Obama and McCain's first two debates took place in Oxford, Miss., and Nashville, Tenn.