Commercial broadcasters shake in their boots over threats to their profits, and then they start stomping around in those trusty old clodhoppers in an effort to alarm the populace. This week the stomps involve Tuesday's commendable and encouraging FCC decision removing two more constraints from the growth of cable television.

Broadcasters have stopped looking upon cable as a pesky puppy and now want it portrayed to the American people as a saber-toothed Doberman pinscher. When the FCC overturned its so-called distant signal and syndicattion exclusivity rules this week, the TV industry reacted with predictable hysterics.

But interestingly enough, in most of the protests that have come foaming out of Washington and New York, the public is rarely if ever mentioned. Mostly there are squeals of anguish over the thought of possible losses in revenue; much talk of the "marketplace," little mention of how all this will affect the customers, the beleaguered viewers of television.

The FCC was thinking of the public, however, when it made the ruling. It wanted to help increase the diversity of choices available to viewers -- something broadcasters oppose. The old rules were complicated, but basically they had made it difficult or impossible for the many cable operators to "import," electronically, the signals of stations in out-of-reach cities. They also put limitations on relaying by cable syndicated TV shows from other markets.

Andy Litsky, spokesman for the National Cable Television Association (NCTA) here, says the rulings, while greatly welcomed, will not affect the majority of cable systems now operating in the country. "Five years ago, the ruling would have been a boon to the industry," Litsky said. "But we didn't have all these satellite services then."

One of the main reasons the typical cable subscriber signs up and gets connected to the wire is the availability of the pay-cable channels, like Home Box Office or Showtime, that go with it. On these channels one can see uncensored and uninterrupted movies and doesn't have to put up with commercials. People do not sign up for cable TV so that they can see "Brady Bunch" reruns from Schenectady rather than from Poughkeepsie.

And yet you would think the FCC had cut a hole in the broadcasters' moneybag from the way they reacted; the ruling is certain to be appealed, first at the FCC, then in court. Technically it could take effect before the end of the summer, but broadcaster opposition may delay it two or three years, or get it thrown out altogether.

"This is ridiculous," trumpeted the perpetually trumpeting Vincent T. Wasilewski, president of the National Association of Broadcasters, in knee-jerk response to the FCC decision. He maintained the ruling was a threat to local stations and the service they provide viewers throughout the country.

"They've been using that argument for nearly 15 years," answers Litsky. "It's been proved totally ludicrous and ill-founded by three years of inquiry at the commission. They found that the size of the local broadcasters' audience was not significantly affected by cable, that their ad revenues were not affected and that the amount of local programming they offered was not related to their revenues anyway, as they had insisted."

Jack J. Valenti, president of the Motion Picture Association of America, is forever searching for possible leaks in the bulging pockets of Hollywood producers. He said that under the new ruling, "basic cable runs rampant, buying on the cheap and getting what it wants with no permission of the copyright owner and no negotiation of any kind."

"Ah, Mister One-Note is at it again," says Litsky of Valenti's remarks.

"It's very funny that while Jack Valenti is running around pleading imminent poverty, all those producers are out there sipping nice tall drinks by pools in Beverly Hills.They are not hurting."

Of course, if broadcasters are not selfless saints toiling tirelessly for the good of the people, neither are cable operators. They're in business, too, and often they seem interested primarily in getting the greatest return for the most minimal effort. The NCTA looks favorably upon a pending Senate bill that would abolish a mandatory access channel as a condition for getting a cable franchise in a community. Access channels give the public direct access to audiences on a cable channel that by law cannot be censored by the cable operator.

But Litsky claims that the Senate bill would not eliminate access and that in fact it has a safe place in the cable scenario. He says the old concept of access-by-demand is being replaced by "community-assisted access," designed to make the access programs tidier and more technically polished. Too bad, because the rough edges and directness of access proved, in some cities at least, to be among its most welcome charms.

As for the FCC decision this week, it's fairly delightful to observe the way networks and stations rush to overreact to it, apparently part of a general posture of viewing any gain made by cable and pay cable as cause for apoplexy to the nth degree.

Top ABC executives Fred Pierce and James E. Duffy did a Fred and Jimmy show on the coast recently to try to persaude TV critics and reporters that when pay TV snared the Duran-Leonard fight of June 20, the American people suffered a terrible loss, and that they were cruelly deprived of seeing it on free TV. What bilge!

In June, Duffy told members of the Broadcasters' Promotion Association that ABC would make available, for free, to affiiliates of any network, materials to be used in frightening viewers into thinking that cable and pay-cable TV threaten to rob them of free television as they know it. The crusade may be marred by the fact that free television as we know it too rarely seems very cherishable. But the war is on.