WASHINGTON (AP) - Conventional wisdom dictates that David Catania is an underdog in the race for mayor of Washington. He is white, a former Republican and openly gay in a city that has only elected African-American Democrats to its top local office.

But Catania, who has never lost an election in the District of Columbia, doesn't see his matchup with Democratic nominee Muriel Bowser that way.

"I've never considered myself an underdog. I've always considered myself very lucky," Catania, an independent who has served on the D.C. Council since 1997, said in an interview Wednesday with Associated Press reporters and editors. "I know if I get up every day and do my best and communicate my message, I know I'll win."

Catania, 46, believes his quest to make history comes down to the contrast between his record and Bowser's, and he doesn't believe voters will define him based on his race, sexual orientation or former party affiliation. Catania left the GOP in 2004 over then-President George W. Bush's opposition to gay marriage, and since then he has championed a number of progressive issues.

Three out of four registered voters in the city are Democrats, and party leaders have pledged to unify behind Bowser following a bruising primary in which she defeated scandal-plagued incumbent Vincent Gray amid historically low turnout. Many voters said they supported Bowser primarily because they believed she was best positioned to oust the mayor, whose 2010 campaign remains the subject of a federal corruption probe. Five people who worked on the campaign have pleaded guilty to felonies.

Before the primary, polls showed Catania roughly even with Gray in a hypothetical matchup but trailing Bowser by huge margins. Still, Catania said he was undaunted by the city's Democratic machine.

"I think it's a paper tiger," he said. "If I ask a voter on the street if they can name one thing my opponent has done, they get a real stumped look because she has a (party) label but she has no record."

Bo Shuff, Bowser's campaign manager, declined to respond to any of Catania's comments.

Becoming the city's first openly gay mayor, Catania said, would be more significant nationally than locally, and he doesn't think his sexual orientation will influence the election.

"Having an LGBT mayor of our nation's capital sends an important message to our entire country about what America is. America is a place where there is equal opportunity, where there is fairness, and it is a place where if you play by the rules, you can succeed," Catania said. "... Having yet another group achieve success through fidelity to those values is an affirmation of what's great about this country. But that's it. We're not going to have fabulous parties."

Catania, who chairs the council's education committee, has made improving the city's public schools his top priority, with an emphasis on narrowing the achievement gap and improving outcomes for poor students. Bowser has refused to yield on the topic, saying that no one will move faster than her on education reform. Neither candidate has committed to retain schools Chancellor Kaya Henderson, who has maintained and fine-tuned the standardized testing policies and rigorous teacher-evaluation system established by her more famous predecessor, Michelle Rhee.

In a city with mayoral control of schools, Catania said the job of the chancellor, whoever it is, would be to execute his vision.

"As mayor, I will be, as the law permits, responsible for schools," he said. "They're not voting for staff. They're voting for leaders."

Throughout the hour-long interview, Catania steered the conversation back to a contrast between his record and Bowser's. He accused her of failing to use her chairmanship of the council's economic development committee to address the city's homeless crisis. Meanwhile, he has pushed through several ambitions education bills - including a costly college scholarship program - with unanimous votes.

Catania is eager to debate Bowser, but her campaign said it would agree to debates only after the general-election ballot is finalized in September.

"There is a reason why Ms. Bowser refuses to debate me: because she has nothing to say," he said.