Chaka Fattah must be getting desperate.

This year's mostly admirable mayoral campaign has seen a few low moments. None was lower than U.S. Rep. Fattah's racially charged dig at rival Democrat Michael Nutter in a debate Monday. During an exchange about police tactics and racial profiling, Fattah gibed that former councilman Nutter "has to remind himself he's an African American."

The comment seemed an ugly bid by Fattah to reassert himself among black voters as the "real" African-American candidate. Fattah has fallen behind Nutter and businessman Tom Knox in recent polls. His remark illustrated his dwindling popularity better than any survey could. (State Rep. Dwight Evans, running fifth in polls, also is African American.)

All of the candidates agree that too many people in Philadelphia are killing each other. Among Nutter's proposals to reduce gun violence is the idea of using aggressive "stop and frisk" tactics to seize illegal guns in high-crime neighborhoods. It's a controversial idea that raises legitimate concerns about racial profiling by police.

Mentioning those concerns, as Fattah and Evans did at Monday's debate, is entirely fair. Where Fattah then took the conversation was not.

You'd never know it from his posturing at the debate, but Fattah himself supports "stop and frisk" tactics. It's right there in the "Fattah Plan for a Gun-Safe Philadelphia." He says he wants to designate police patrols to seize illegal guns from people. To quote from his campaign's web site, "This targeted enforcement has been proven to be effective in other cities," singling out Kansas City and Indianapolis.

Police in both cities have used "stop and frisk" tactics to get guns off the streets. In Kansas City, these random gun seizures were credited with reducing gun violence by 49 percent.

Nutter and Fattah are talking about the same thing in different ways. Nutter is open about backing "stop and frisk" tactics. Fattah, trying to make up ground with black voters, quietly endorses the idea in policy papers while leaving TV viewers with the impression that he opposes it.

In a rich bit of irony, Fattah accused Nutter of making a "racial appeal" because Nutter pointed out that the vast majority of shooting victims are black. Actually, it's Fattah's campaign that has been the most prone to targeting messages to black voters.

Other African-American leaders in the city, such as Councilman Wilson Goode Jr., recognize that the city's rising murder rate is driven largely by black-on-black gun violence, involving mostly young males. Goode argues that the first step toward addressing this tough problem is defining it honestly.

Nutter shouldn't be castigated as a racial impostor for doing so.

Nutter's crime proposals surely raise valid concerns. His proposal to declare a "state of emergency" is fraught with downsides.

Clear and candid thinking is essential. Fattah's performance Monday night was just the opposite.