IS THERE any voter, or television watcher, who does not feel dismay when he sees another negative political ad come on the air? As this fall's campaign has proceeded, more and more candidates have decided to attack the opposition rather than boost their own products. It is a matter for concern.

Granted, negative ads are tempting. American voters say they are in a sour mood. They distrust politicians, and they think government doesn't work very well. A candidate is bound to emphasize messages that will work in his behalf and be credible with the voters. In the current climate, that often means negative messages.

Nor is there anything necessarily illegitimate about attacking an opponent's stance on an issue, or his personal qualifications, if the charges are accurate and are presented in a fair context. When a negative ad does go too far, it usually boomerangs. This is apparently what happened when California Senate candidate Jerry Brown ran ads showing various celebrities saying, "I want to live," implying that his opponent, Pete Wilson, was of a different view because he opposes a nuclear freeze. That ad was yanked after six days. Similarly, in Tennessee, Senate candidate Robin Beard's ad charging that his opponent, Sen. James Sasser, supports Fidel Castro seems to have been counterproductive. So have ads run by Sen. Harrison Schmitt (R-N.M.) attacking his opponent's actions as state attorney general.

The free marketplace of political ideas does exert reasonable discipline on negative advertising, insofar as it affects the fortunes of individual candidates. Its effect on the political process is something else. Continuing barrages of negative advertising intensify the negative tone of political discourse, not only among candidates but among their constituents.

Many constituents do have corrosively negative feelings about politics; politicians echo those feelings. Yet how many voters really want to change our system in a fundamental way -- to tip the balance between public and private sectors, for instance? Not very many. We have a hunch that voters, accustomed though they may be to expressing dissatisfaction, may be hungry for affirmation of the strengths of the nation and even its political system. Ronald Reagan, when his economic program did not seem to be failing, may have been prepared to wage such a positive campaign. Now few politicians are. Is it possible that they are missing out on a winning strategy?