Police Practices Take Center Stage at G.O.P. Mayoral Debate Facing off in a televised debate on Wednesday, the leading Republican candidates for mayor vowed to fully support the Police Department and to limit the role of an inspector general that would monitor the department. With two months until the primary, the Republican candidates used the debate, hosted by NY1, to try to distinguish themselves in a race where most of the public's attention has been focused on the Democratic candidates. One of the leading Republican candidates, Joseph J. Lhota, a former chairman of the Metropolitan Transportation Authority, suggested that if a measure that would expand the definition of bias-based profiling ultimately became law, he would seek to challenge it in court. The measure passed the City Council last month, as did another that would create the inspector general position, but Mayor Michael R. Bloomberg is trying to stop at least the profiling measure from becoming law. Mr. Lhota's main rival, John A. Catsimatidis, a billionaire grocer, said he believed more training was necessary for the police. Showing his penchant for unusual ideas, he also suggested that police officers be given hand-held metal detectors - "magic wands," as he put it - that they could use during stops. "Just like the airports," he said. You just go over the suspect and you don't have to frisk him, and you find out if he has a loaded gun. Another Republican, George T. McDonald, who has struggled to attract support for his campaign, said the focus on police tactics was obscuring the need to focus on what he said was the underlying problem, of joblessness. Part of the challenge for the Republicans has been simply getting voters to remember them. A Quinnipiac University poll conducted in late June found that nearly half of Republican voters in New York City did not yet have an opinion of Mr. Lhota, while nearly two-thirds had no opinion of Mr. Catsimatidis. Nine in 10 Republican voters were unfamiliar with Mr. McDonald, the founder of the Doe Fund, a nonprofit organization that works with the homeless. The debate highlighted some areas of tension between the leading candidates. Mr. Catsimatidis, for instance, questioned why Mr. Lhota had not blocked increases in tolls when he led the authority. "A lot of people are concerned that you could have done more," he said. Mr. Lhota said that the blame rested with Albany. The candidates also differed over the handling of expired labor contracts with city workers. "No one is entitled to retroactive pay - at all," Mr. Lhota said. But they are entitled to a fair wage from this point going forward, and there's money in the budget to be able to do that. Mr. Catsimatidis faulted Mr. Bloomberg for the expired contracts. "It's wrong," he said. The city should have sat down with them, and they should have negotiated. Hey, if they didn't have enough money, there was always room for a half a percent or 1 percent. All three of the Republicans would face a difficult path to victory in November's general election, as Democrats outnumber Republicans in the city's electorate more than six to one. Mr. McDonald, in particular, sought to make inroads at the debate by sparring with Mr. Catsimatidis. At one point, he brought up a remark by Mr. Catsimatidis in a little-noticed interview in which he predicted Mr. McDonald's candidacy would eventually disappear. Was that a threat? Mr. McDonald asked Mr. Catsimatidis. Mr. Catsimatidis looked incredulous. "That sounds like a Mafia thing, making me disappear," Mr. McDonald added. Mr. Catsimatidis affirmed that he was not threatening Mr. McDonald.