AS A THIRD of the nation's senators look toward the 1986 reelection battles, some are also casting a nervous, cockeyed look back at the big winners of the last war.

Namely, a hound dog and a lizard.

The droopy-eared canine starred in campaign commercials last year that played up former Kentucky Sen. Walter D. Huddleston's absenteeism (a bloodhound searches far and wide, never finds senator).

The lizard carried the attack against Illinois Sen. Charles Percy's inconsistencies (a chameleon changes colors before viewers' very eyes).

As negative spots go, these were pretty tepid. But both got their men -- and in Huddleston's case, that was no small trick, given the 29- point lead he had enjoyed over his longshot Republican opponent, Mitch McConnell, less than two months before the election.

The Senate incumbents have taken heed and gone into a protective crouch. They are toying with schemes to keep such attack ads off the air in 1986. The happiest thing to be said about their proposals is that they're likely to go nowhere.

One bill, known as the Clean Campaign Act of 1985, would provide that any candidate for federal office referred to on the air by any stand- in (animal or human) for his opponent would be entitled to free response time. Only when the opponent has the gumption to go in front of a camera and do the dirty deed himself or herself would the provision be waived.

At its first hearing in the Senate Commerce Committee this month, the bill evoked a series of wounded laments from incumbents about the sorry state of modern campaign ethics.

"It's a sickening . . . revolting mess," Danforth said of the proliferation of attack ads. "There is a revulsion at these unethical, immoral ads," said Sen Robert Packwood (R- Ore). "The most disgusting development in politics in my lifetime," said Sen. Barry Goldwater (R-Ariz.). "The sleaziest new element in politics (and maybe) the most dangerous," said a statement by retired Senate Majority Leader Howard Baker.

Never mind that the proposed remedy appears on its face to be unconstitutional -- a point that the Amercian Civil Liberties Union quickly made, and that even some of the bills' cosponsors quietly concede.

Let's consider these dastardly ads themselves. They are the handiwork of a burgeoning campaign consultant industry that has found the surest way to unseat an incumbent is to bash him upside the head -- figurately, frequently and, if possible, on TV.

It has also found that once attacked, a politician had better defend, retaliate in kind, or do both. What he cannot do is ignore.

These are hardly startling discoveries. Political attacks are as old as politics; indeed, they are the very guts of politics. As Packwood pointed out, the broadsides of a century ago ("Ma, ma, where's my pa? Gone to the White House, ha, ha, ha," was the campaign jingle that reminded voters about stories of President Grover Cleveland's illegitimate child) make today's look polite.

But senators and reformers argue that televison adds a lethal potency to this ancient game, takes it from conventional to nuclear weaponry, in the methaphor of election analyst Curtis Gans, and as a medium is best suited to create doubt, stir fear, exploit anxiety, distort facts. No wonder, says Gans, fewer and fewer people bother to vote.

It doesn't wash. Attack ads are, for better or worse, the very dialogue of modern political campaigns. They are the places where the issues are joined, where images are shaped and reshaped, where appeals are boiled down to their essence.

Are they illuminating? Rarely.

Are they unfair? Often. But they are dialogue. And they do get through. And they do expose themselves to the most powerful regulating agent of all -- the common sense of the voter.

The key truth about negative ads is sometimes they work and sometimes they don't. "More candidates pay to defeat themselves than to win," media consultant Charles Guggenheim reminded the Senate panel.

The most notorious attack ad of 1982 featured an actor dressed up as Fidel Castro lighting his cigar with a dollar bill and saying "Muchas gracias, Senor Sasser," to imply some of Tennesee Sen. James Sasser's votes had aided the communist dictator. The ads overdid it; Sasser won with 62 percent.

Take away a candidate's opportunity to make these kinds of scurrilious attacks, and what kind of ads would the public be left with? Terry Dolan, chairman of National Conservative Political Action Committee and one of the founding father of the modern hit-and-run political ad, thinks he knows.

On the day of Danforth's hearing, Dolan joined with the ACLU in denouncing the bill. He also showed an ad from the senator's last campaign in which visuals of Danforth playing with his children were shown as an announcer chirped in: "Jack Danforth knows at least four Missourians who'll be living here long after he's finished serving in the Senate. So when he talks about making the system work for the future, he's not kidding."

"If somebody is looking for ads to outlaw," said Dolan, "we recommend them. They do nothing but sell a candidate like a bar of soap."

Dolan calls the bill a blatant incumbent protection measure; incumbents are the ones with records to attack. He's right. It is also unnecessary and unworkable.

At the hearing, Huddleston's former colleague, Sen. Wendell Ford (D-Ky), came up with a far more practical form of incumbent protection.

"We all know that old Dee used to work in his office late at night. What about a response ad that took that hound dog, had him walk through the darkened corridors of a Senate office building, go through a door and find Dee at work drafting a bill. An announcer says, 'Found you at last -- working for the people.'"

Would it have worked? Dee Huddleston probably wishes he'd tried to find out.

Paul Taylor covers politics for The Washington Post.