By now, everyone is used to politicians promising the moon and the stars. Now come politicians promising a lawsuit.

John Street, borrowing a page from State Rep. Dwight Evans' playbook to be the Democratic nominee for mayor, has announced that, if elected, he will sue gun manufacturers for the violence their product produces.

Not to be outdone, Sam Katz has quickly made the same promise.

Is it a good idea?

Mayor Rendell was the first one to float it, saying two years ago he was strongly considering launching a lawsuit. It would have been among the first of its kind.

But along the way, Rendell lost his nerve, citing concerns about legal cost and whether the city could win. But 27 other cities, including Chicago and New Orleans, have pressed forward with lawsuits. And according to a recent Wall Street Journal story, the lawsuits are having a good effect on the irresponsible gun industry.

The lawsuits are forcing some of the smaller, less-profitable gun companies to close up shop, which will likely reduce the number of guns that are churned out like link sausages.

With less competition, the major gun manufacturers will likely increase the price of their guns, making it even more difficult for people to buy a gun - people like Larry Gene Ashbrook, who slaughtered seven people and injured seven more in a Fort Worth church last week. Or Richard W. Spicknall, who was able to buy a gun despite a protective order obtained by his wife and use it to kill his 3-year-old daughter and 2-year-old son.

So clearly, to us, the idea of Philadelphia joining the suit is a worthy one. It's time that this city - among those with the highest number of gun-related homicides in the country - made its voice heard in the courts.

We're going to remember that Street and Katz have made this pledge. And, come January, when one or the other is sworn into office, we intend to remind them.