These columns have been defending Second Amendment rights against the Bloomberg administration, but there comes a point where the gun-dealers cross the line to indefensible, and the Daily News had a story this week about one such line. It turns out that Lauer Custom Weaponry in Chippewa Falls, Wisconsin, is selling what it calls the “Bloomberg Collection” — decorative gun finishes in “Manhattan Red,” “Bronx Rose,” “Brooklyn Blue,” “Queens Green,” and “Staten Island Orange.” The company’s Web site features a machine gun pointed menacingly at Mayor Bloomberg’s head.

It’s a display not of sportsmanship or self-defense but of bad taste, and it could inspire something terrible. To make fun of Staten Island — where two New York police officers were murdered in cold blood while trying to prevent criminals from gun-running — in this context is disgusting. Politicians understand before getting into public life that they will be the target of vilification. That comes with the territory. But having a machine gun pointed at one’s head, even artistically as an illustration, is another matter. It is outrageous in and of itself and damaging to all of us who cherish rights that are vouchsafed by the First and Second Amendments.