A mayoral campaign that is growing surprisingly competitive is growing predictably nastier as the two candidates yesterday traded criticism in another of their series of debates.

Mark DeSantis, the Republican challenger whose campaign has gained traction in the form of newspaper endorsements, faulted Mayor Luke Ravenstahl for sending out a mailing to Pittsburgh residents noting that Mr. DeSantis had supported former U.S. Sen. Rick Santorum and President Bush. However, the flier failed to mention other candidates -- including some Democrats -- that Mr. DeSantis has backed.

Speaking before a crowd at Point Park University's GRW Theater, Mr. Ravenstahl defended the flier, saying it "was appropriate" because "it highlighted something that the voters should understand."

"You supported those candidates' policies," he said. "Since the Bush administration, we've seen a significant, significant decline in federal dollars coming to the city of Pittsburgh: $21 million under the Clinton administration down to $16 million annually. Community Development Block Grant dollars that are used to grow jobs, invest in our infrastructure, to rebuild our communities.

"He hasn't been afraid to talk about my record. I know why he wants to run away from his. Because those policies don't line up with the voters of Pittsburgh, and that's something I think they should know."

"Luke, I'm not running away from anything," Mr. DeSantis responded. "You do this silly mailer when you've run out of things to say."

The exchange was among those featured in the televised debate sponsored by the university, KDKA-TV and the League of Women Voters.

As in previous debates, the questioners -- members of the KDKA-TV news staff -- hammered at Mr. Ravenstahl's ethical indiscretions during the 13 months he has been in office. Moderator Ken Rice began the debate by asking how voters could trust the mayor when there is the perception that he had "lied or been deliberately evasive."

Mr. Ravenstahl, 27, said that as a new mayor he failed to appreciate what would be demanded of him. "You learn from your mistakes and move on," he said.

"We all make mistakes," Mr. DeSantis said. "What I didn't hear was a humility, a recognition that these were truly bad decisions. I hear him admit that he made mistakes, but I don't hear him say specifically what he is accountable for in those mistakes. And some of those mistakes were pretty serious."

Mr. Ravenstahl asked that voters judge him by his accomplishments in office, pointing out that he has submitted a balanced budget and put the city on the road to financial recovery.

"I have pledged to not issue debt over the course of the next five years," he said. "That's unprecedented in the city of Pittsburgh's history. My generation and our administration was handed a fiscal nightmare. We've attacked it head-on, we're going to continue to attack it head-on."

"I would maintain that fiscal responsibility is important, but that's the minimum performance for any government," Mr. DeSantis countered. "It's a given that a city must be fiscally responsible. It's hardly cause for celebration."

Asked about his own qualifications for the job, Mr. DeSantis, 48, pointed to his years as a businessman and consultant in Washington, D.C.

"I just wish there were a few more entrepreneurs in our local government then they'd understand that when they do something -- perhaps layer in a new tax or do something to affect businesses -- they'd truly understand what it means to actually start a business and grow a business," he said.

When the two men had a chance to ask each other a question, Mr. DeSantis wanted to know how much money the mayor expected to bring back from the state capital.

"I'm not going to Harrisburg with my hand out," Mr. Ravenstahl said. "I'm going to Harrisburg to build bridges, to communicate with them, to show them that we're continuing to live within our means."

Mr. Ravenstahl then said his campaign would be sending out another mailing this week noting numerous endorsements he had received from local and state elected officials. How, he asked, did Mr. DeSantis expect to be able to work with leaders who had opposed his candidacy?

"I don't worry about what other politicians think of me. I focus on what matters," Mr. DeSantis said. "As long as we focus on the interests of the people that live in this city, we'll get along with any politician."