WHILE MADISON AVENUE regularly leaves me stunned and flabbergasted, it's rare that advertisements leave me angry. But certain political ads the Democrats and Republicans are gearing to black audiences have raised my political temperature to the boiling point.

If the candidates, particularly Ronald Reagan, have been safely mealy-mouthed in their articulation of civil rights concerns, their surrogates have shown no such reluctance in periodically hitting blacks with insulting ads designed to buy their votes on the cheap. On black-oriented radio stations, for example, the Republicans have been running an ad giving a laundry list of alleged Democratic sins -- unemployment, inflation, waivering foreign policy -- interspersed with the syrupy voice of a woman saying: "Democratic leaders don't make your juices run!"

The ad tells us just where some campaign strategists think the black intellect is and how arrogantly they feel the black vote can be treated.

Another ad appearing in magazines features a picture of President Carter with Supreme Court Justice Thurgood Marshall in his judicial robes and Patricia Roberts Harris, Secretary of Health and Human Services. In bold black type, it says: "Jimmy Carter named 37 black judges. Cracked down on job bias. And created 1 million jobs."

Beneath the picture it says in smaller type, "That's why the Republican's are out to beat him."

Now it doesn't say explicityly that Thurgood Marshall is one of the judges Carter has appointed. But it is implied, and it isn't true. Yet Democratic campaign chief Bob Strauss knows that judicial appointments (or the lack of them) are one of blacks' biggest fears of a Republican president. And Gerald Rafshoon, Carter's former media advisor, knows that Marshall is a venerable civil rights hero who won the 1954 school desegregation case before the Supreme Court.

This is actually the second time around for the ad. President Carter's reelection campaign organizers decided to stop running it in September for reasons that have nothing to do with my objection to it.

At that time, Carter had made statements in Atlanta linking Reagan to "code words" of racism, and Rafshoon's communications firm said they were pulling the ad -- that ran in about 100 black-oriented newspapers across the country in September and was scheduled for Jet, Ebony, Black Enterprise and Essence magazines -- presumably because they implied Reagan was a racist. a

But I happend to be leafing through an Oct. 23 copy of Jet magazine a few days ago and to my surprise I found the ad is still being used. I think this is blatant exploitation of Thurgood Marshall, and I'm frankly surprised the American Bar Association has not spoken out. Ever since Marshall became the first black ever named to the court in 1967, he's shunned the spotlight.

A Rafshoon spokesman explained that his company thought all four magazines were monthy publications with ad placement deadlines that had already passed when the company decided to yank the ads. He was right about Ebony, Essence and Black Enterprise, but wrong about Jet. Jet is a weekly with more frequent deadlines. There was time to pull the ad there.

It was not pulled, "through an oversight in our company," the spokesman said.

The Democratic and Republican parties take a foolish kind of comfort if they think the issues are so easily dismissed. It is clear to many blacks that the prime issue today is not so much civil rights as economic rights. And many whites are no better off than are some blacks. Ronald Reagan made a telling point when he advised voters to ask themselves whether they are better off today than four years ago. Most whites as well as blacks have to say no. Everybody has to say no.

Sometimes I think the idea behind these intellectually insulting political ads is to keep us angry and thinking about race to deflect us from the real issues -- the economic one. Neither candidate had addressed himself adequately to the economic issues that trouble us all -- why employment, which should be a right, is for many an unobtainable privilege, why owning their own home is a luxury increasingly fewer young Americans can afford, why the decay of our cities is deepening rathan than abating, upping the social and financial ante we all must pay.

Yes, Reagan's directive for us to ask ourselves whether we are better off today than four years ago makes a lot of sense than his ad about the Democrats not making our "juices run."

The real problem is that when we vote four years from now and look back at 1980, our response most likely will be the same as it is today. And therein lies the proper challenge for statesmen worth the name -- finding an answer to that problem rather than trading it for political gain with snappy slogans.