D.C. Council member David A. Catania filed paperwork Wednesday to run for mayor as an independent, ensuring an unusual November challenge for the Democratic primary winner and perhaps the most competitive general election for mayor that the overwhelmingly Democratic city has ever seen.
Mr. Catania, who was first elected to an at-large seat on the council as a Republican in 1997 but later changed his affiliation to independent, said he decided to run because he was unsatisfied with the slate of candidates currently in the race. He said he was undeterred by the fact that every mayor elected since residents began voting for the office in 1974 has been a Democrat.
“Labels are fine, but I think the people are looking for a leader who’s actually delivered,” said Mr. Catania, 46. “There is one thing I can say: I have delivered. The others have talked a good game, and good for them for having labels. But I’ve actually delivered.”
Mayoral elections have, by and large, been decided by the city’s Democratic primary — this year set for April 1 — with general elections more often a formality.
The closest general election for mayor in the city’s history was separated by 14 points, when Republican Carol Schwartz in 1994 was defeated by Marion Barry, who sought a third term in office after being jailed for smoking crack cocaine.
But Mr. Catania polled well even before formally entering the race. A January survey in The Washington Post put a hypothetical head-to-head race between Mr. Catania and Mr. Gray in a dead heat, with Mr. Gray ahead 43 percent to 40 percent among registered voters.
And Mr. Gray’s status as the front-runner is in jeopardy with the guilty plea this week of a businessman who financed a more than $600,000 off-the-books campaign on behalf of his 2010 campaign.
Whether it’s Mr. Gray who emerges from the primary or one of seven other challengers, four of whom are his D.C. Council colleagues, Mr. Catania pointed to both his legislative record and a series of re-election victories as strong suits.
“I’ve won more citywide races than everyone else in the race combined,” he said, referring to his five victories as a candidate running for one of the two at-large seats reserved on the council for non-Democrats.
In his last re-election in 2010, Mr. Catania received 57,163 votes — a total that corresponds to roughly 42 percent of those who cast ballots in the election.
“I think Catania has been very successful in D.C. politics so far. He passed a lot of difficult legislation,” said Paul S. Herrnson, executive director for the Roper Center for Public Opinion Research at the University of Connecticut and a longtime D.C. political observer. “He’s charismatic in an understated way. He has a good way with people. That’s a start.”
But challenges, like the aforementioned labels, could be an obstacle. Of the more than 446,000 registered voters in the District, about 76 percent of them are Democrats, with 6 percent saying they are Republicans and 17 percent declaring no party affiliation, according to the most recent statistics from the D.C. Board of Elections.
And as a white, gay candidate with no party affiliation, he might face more of an uphill battle to gain supporters than whoever wins the Democratic primary.
“He’s got one strike against him in that he doesn’t share the political and demographic characteristics as most of the voters,” Mr. Herrnson said. “Also some conservative voters may not be as inclined to support his campaign based on some of his social issues.”
One of the city’s two openly gay council members, Mr. Catania left the Republican Party in 2004 after President George W. Bush and party leaders supported a constitutional amendment to ban same-sex marriage. In 2009, he authored the bill that recognized gay marriage in the District.
Known for his prosecutorial style and his quick temper, Mr. Catania previously oversaw the D.C. Council’s health committee and was a staunch advocate for keeping open United Medical Center, the only hospital east of the Anacostia River. His support fueled a high-profile spat with the city’s then-chief financial officer, Natwar M. Gandhi.
But after appointment last year to oversee the D.C. Council Committee on Education, Mr. Catania has made education reform one of his top priorities.
“It is the difference between whether or not we will at long last end the income inequality and divisions in this city,” he said.