LAS VEGAS -- In an age when militants are showing new strength in their efforts to crush contrary ideas, American booksellers find themselves not just merchants but moral mediators as well.

Book banning and other forms of intellectual harassment, like those efforts now aimed at art, are current and proliferating. And booksellers are getting organized to cope with their new role as First Amendment police.

At one of several sessions here at the American Booksellers Association's annual convention, best-selling young-adult author Judy Blume declared that her earliest books, besieged by censors and would-be censors when they first appeared, might not have been published at all in today's hostile environment.

Oren Teicher, president of the ABA Foundation for Free Expression, noted that J.D. Salinger's "The Catcher in the Rye," a classic modern target of mindless censorship though tame by today's standards, was banned by a public library system as recently as last fall.

The new foundation, which was inaugurated during the convention, puts the booksellers association, with nearly 5,000 members, on record as an industry against censorship, and holds the promise of organized and better-informed responses to local censorship crises.

The foundation, with a $150,000 first-year budget, is one of a string of responses by such kindred organizations as the American Library Association, PEN and the Association of American Publishers, with which the ABA foundation works in concert.

During 1989's Salman Rushdie affair, with its anonymous death threats and bookstore firebombing episodes, issues of free expression found themselves jostled by those of public and private safety.

The continuing struggle for most book dealers, however, is against slightly less violent forms of thuggery -- still predominantly from the evangelical right, but increasingly from the feminist and ethnic left.

A recent case in point was Village Books, in Bellingham, Wash., where feminist activist Nikki Craft has been campaigning to remove the current issue of Esquire, with its cover package on "The Secret Life of the American Wife," which includes such material as "Your Wife: An Owner's Manual."

In late May, Village Books owner Chuck Robinson said, Craft entered the store and tore up four copies of the magazine. Village had her arrested, and Craft, now in jail, won't post bond until the bookstore capitulates and sends the offending issue back to Esquire.

Robinson, who says he has since been visited by zealous Craft partisans, allowed as how Esquire might have "a few things that don't seem to be quite in tune with the '90s," but even though the ideas are offensive to many people, "they are nonetheless ideas." If suppressing objectionable material amounts to "civil disobedience," as Craft has claimed, Robinson said, "Mr. Thoreau, Mr. Gandhi and Dr. King ... are rolling over in their graves."

Washington bookseller Parker Orr, manager of the Olsson's store in Dupont Circle, offered evidence that confronting censorship is not as simple as it might sound, or as it once was. He cited the example of a Louis Farrakhan book that Olsson's has been selling at its downtown location despite some objections.

The store had misgivings about selling the book, Orr said, but the decision was made on a fundamental freedom-of-ideas (and free-market) basis: The customers were asking for it. The ABA's Teicher announced a gratifying public response to its recent full-page newspaper advertisements, placed in conjunction with Waldenbooks. More than 75,000 readers have returned coupons supporting the credo that "Americans have the right to buy, stores have the right to sell, authors have the right to write, and publishers have the right to publish constitutionally protected material."