In the Pennsylvania primary six months before the election in November, the decisions of the Carter-Mondale campaign to release an unfavorable poll and to put on the air commercials attacking Edwary Kennedy suggest that the presidential race is fast becoming Ronald Reagan's to lose and not Jimmy Carter's to win.

The released Carter poll, replete with "adjusted" figures, reported that the president is trailing Kennedy in next Tuesday's primary by three points. Nobody knows what the "unadjusted" (if there were any) figures showed, but one can guess why the numbers were made public. An unfavorable poll is no help to volunteer morale or campaign fund-raising, but it does serve the purpose of making one's opponent the issue in the voting. The objective was to shift the spotlight in Pennsylvania from Jimmy Carter to Edward Kennedy.

The same rationale explains the Carter decision to spend hundreds of thousands of dollars to broadcast not the triumphs of the president but rather the travails and trespasses of his challenger -- to make Kennedy the unacceptable alternative. It's straightforward. It has worked before during this primary season and it may very well work again next Tuesday. And Ronald Reagan can expect much more of the same starting long before next Labor Day.

Urging citizens to vote against his opponent rather than for him is the only strategy currently available to the president and his supporters. Jimmy Carter is truly the remainderman of national politics. He gets what's left over after his opponenets have taken theirs by being the least unacceptable alternative to the greatest number of voters. Carter has never had an intense ideological or personal constituency and has not developed one in office, at least not below the level of GS15. Reagan has just such a constituency, so if it's intensity of support you're measuring, the president starts out behind. i

Bot Strauss and some of his colleagues at Carter headquarters are smart. They know that, to win in November, they must succeed in demonizing Reagan for a majority of voters. Carter, because of his record in office, is now denied the traditional Democratic theme song of the economy (and how the Republicans would foul things up). The present issues are of little help. Taxes, inflation, interest rates, stronger defense, the balanced-budget fever and the anti-government push all work for Reagan and against Carter.

So to beat Ronald Reagan in November, the task is clear: Reagan must be made the Barry Goldwater of 1980. Reagan, or the prospect of Reagan as president, must be so fearsome as to persuade people to reelect Jimmy Carter.

While the task is clear, its execution could be terribly difficult, especially if Reagan refuses to cooperate.

First, Ronald Reagan is not Barry Goldwater and this is not 1964. Goldwater was not the popular choice of his party in 1964. Reagan is most definitely that. Goldwater was a senator from a small, very Republican state. Reagan was for eight years the chief executive of our most populous and arguably most complex state. He found a deficit and left a surplus in Sacramento.

Unlike the popular perception of Goldwater 16 years ago, Reagan, in this campaign, has generally come through to voters as a likeable and non-threatening human being. His sense of self and sense of humor have enabled him to win unambiguously two successive candidates debates, in New Hampshire and Illinois. When was the last time that happened in a national campaign? Reagan has revealed no mean side, up to now, and absolutely none of the compulsive striving so evident in his fellow Californian and Republican, Richard Nixon. Nixon, even in the White House, seemed too often some sad character out of a John O'Hara story with his nose pressed against the country-club window waiting in vain for both invitation and acceptance. There is none of that visible in Reagan.

But if you're either running with or rooting for Jimmy Carter, you know there are any number of mistakes that Reagan can make. For instance, Reagan could heed those counselors who are urging a 1980 southern strategy for the general election. Reagan is an accomplished political performer and, like all good political performers, including Carter, Reagan never forgets his immediate audience. In Charleston or Mobile, chances are he will drop the "ic" from Democratic. In Buffalo or Bridgeport, he will not. And it's in New Haven, not New Orleans, where Reagan can win this campaign; it's in New Haven and in Camden and in Scranton where the Reagan appeal to the people who pack their lunch and punch a clock can capture the base of the Democratic Party. To beat Carter in the South, Reagan would have to emphasize the conservative cultural issues, and even then he might not be able to overcome regional pride. And the message necessary to win in the South does not travel north of Richmond. But the Northeast Reagan message, emphasizing tax cuts and traditional values, does travel south. Even more important, any day Reagan is in Pittsburgh or Rochester, he will be on the network news that night. That is simply the way the system works.

While Reagan seems to be free of any of the so-called "character" problems that have crippled Kennedy's candidacy, he does have at least traces of what could be called the Mario Procaccino Syndrome.

For any who may have forgotten, Procaccino was the 1969 Democratic candidate for mayor of New York against an immensely unpopular incumbent, John Lindsay. Procaccino's malapropisms and all-round ineptness were not enough by themselves to squander a hugh lead that year. But Lindsay ran on one single theme from beginnning to end: "It's the second thoughest job in America." Through endorsements and advertisements, the Lindsay message that the job was too big for Mario Procaccino finally got through. Right now, the only demonizing route open to the president's men against Ronald Reagan might very well be called Marion Procaccino Revisited. After all, Jimmy Carter has never had a subway strike.