Those who reckon that Senator McCain is so similar to Mayor Bloomberg that there’d be no logic to an independent presidential run by Mr. Bloomberg will want to have a look at Mr. McCain’s remarks prepared for delivery last week to the American Conservative Union’s annual CPAC conference. Said Mr. McCain, “I have defended my position on protecting our Second Amendment rights, including my votes against waiting periods, bans on the so-called ‘assault weapons,’ and illegitimate lawsuits targeting gun manufacturers.”

The very lawsuits that Mr. McCain dismisses as “illegitimate” include one pursued by Mayor Bloomberg’s city law department together with the Brady Center to Prevent Gun Violence. The suit, City of New York v. Beretta, is awaiting a decision from judges who ride the Second Circuit. It names not only Beretta but also Colt, Glock, Smith & Wesson, Browning — the whole lot. It’s hard not to see such remarks as a shot across the bow of a mayor who views gun violence as a high priority national public health issue. Mr. Bloomberg, for his part, is pressing ahead. Today he will be at Baltimore City Hall for a regional summit of the Mayors against Illegal Guns.

On guns our own views are closer to Mr. McCain’s than to Mr. Bloomberg’s. But as Governor Huckabee’s win in Kansas over the weekend shows, Mr. McCain, while close to cinching the nomination on the basis of the delegate-count math, has not yet closed the sale to the Republican grassroots. He is, in other words, politically vulnerable. We don’t suggest Mr. Bloomberg could beat him on guns — both the Constitution and American tradition are on Mr. McCain’s side of the argument.

Even for those of us who differ with Mr. Bloomberg ‘s position on guns, however, can admire him for his refusal to tailor his principles to politics. And can mark the point that all the talk about how the accession of Mr. McCain obviates the need for an independent in the race doesn’t comport with the stands on the issues these politicians have taken. Surely Mr. Bloomberg — as someone, who, unlike either Senator Clinton or Senator Obama or Senator McCain, has actually overseen a police force and borne responsibility for a crime rate in a major city — has a voice that would be worth hearing on this, not only from the sidelines but in the middle of the fray.