SOME OF THE biggest bluffs in New Hampshire -- those gun-worshippers who revel in bullying candidates on the issue of gun controls -- had a field day in the main ballroom of the Highway Hotel in Concord the other night. Having conned eight presidential candidates and a sitting-in president's son to their one-issue forum, more than 1,000 disciples of the National Rifle Association -- some bearing arms and many others with an arsenal of loaded questions -- exacted homage from all but one of their hostages, Rep. John Anderson. Only Mr. Anderson stood up to booers and booters with a forthright call for better controls on handgun traffic. The gun-owners' least favorite candidate, Sen. Edward Kennedy, did not attend.

The trouble is, the gun-owners' bluff has been all too effective. It seems to have quieted Mr. Kennedy, who has had all the cause in the world to lead legislative campaigns over the years for the best possible federal controls on gun traffic. He has been downplaying his previous support for tight protective measures. At the Concord meeting, his workers circulated a leaflet urging the gun-owners to "compare Carter and Kennedy on gun control." It quoted Mr. Carter as saying in 1976 that he favored registration of handguns and a ban on the sale of cheap handguns, and it went on to state that "Senator Kennedy does not want to take your guns away."

Who is seriously advocating the disarmament of sportsmen? National polls have shown time and again that a solid majority of Americans support federal handgun controls to place some responsibility on handgun ownership and handgun commerce. But if Mr. Kennedy is soft-pedaling the issue, how about the rest of the pack? Jerry Brown charged his Democratic opponents with trying to abridge a constitutional right.George Bush coupled a recitation of his long opposition to controls with a somewhat twisted explanation of his voting record in the House. Howard Baker extolled the virtues of "rugged individualism." Jack Carter talked about his father the quail-hunter. John Connally, with photos of himself with shotgun at the ready, said, "I grew up in south Texas with a gun in my hand as long as I can remember." And Philip Crane, Bob Dole and Ronald Reagan also sing the praises of guns.

These are the sour notes of single-issue politics that candidates feel compelled to strike in primaries. Yet two million new handguns are added each year to the civilian arsenal -- now past the 50-million mark -- while hundreds of thousands of Americans are killed, wounded or threatened with handguns every year. When will the candidates stop listening to that narrow segment of voters that regards any thoughtful effort to slow down the slaughter as a political capital crime?