IT IS a staple of this year's cynical political wisdom that running for office is what Jimmy Carter does best. We have a different view. We think it may be what he does worst. Mr. Carter, as a candidate, tends to convey a mean and frantic nature. This has been demonstrated in many ways over the past several weeks -- and months.

First, the president seems determined to discredit, rather than to prevail over, his opposition. It's as if he doesn't quite believe they are entitled to run against him, and so he won't actually fight them, but rather will only provide an endless series of complaints about their candidacies and their character. You don't have to be a John Anderson fan to be made uncomfortable by the way in which Mr. Carter has sought to paint the Anderson effort as somehow illegitimate , not entitled to a hearing. And you don't have to be a Reagan fan to have noticed that Mr. Carter has abandoned all dignity in his round-the-clock attack on Mr. Reagan's character and standing, jumping (in a most sanctimonious tone of voice) for "offenses" similar to many Mr. Carter himself has committed, and, most recently, concluding from all this that Mr. Reagan is a "racist" and a purveyor of "hatred." This description doesn't fit Mr. Reagan What it fits, or more precisely, fits into is Jimmy Carter's miserable record of personally savaging political opponents (Hubert Humphrey, Edward Kennedy) whenever the going got rough.

Ronald Reagan is not a hater and he is not a racist; there are real reasons to challenge his claim to the presidency, but these are not those reasons. Mr. Carter's "evidence" for his charges is so weak as to be pitiable and also puts one in mind of a series of comparable failures and defaults of his own over the years, from "ethnic purity" in 1976 to silence on the civil rights bill in 1964 that could as easily have been distorted by an opponent. In a way, the most disturbing feature of the Carter campaign technique is that he displays a certain contempt for the evidence of our own eyes , asserting these things that run counter to what we can see and already know, as if he believed it didn't matter, that people would believe anything they were told. Only the day before his racism-and-hatred remarks, for instance, Mr. Carter -- the man who has managed to keep out of debates with his competitors for a year now, and who has reduced his press conferences to the merest trickle -- was telling the public, in his most outraged-for-democracy fashion that it was a terrible thing that Mr. Reagan was refusing to be "cross-examined" as anyone who aspired to the presidency should be.

So the president calls names, and he baldly recreates his own record (for the better) and that of everyone else (for the worse) and he displays an alarming absence of magnanimity, generosity and size when he is campaigning. No, of course, the other candidates are not just going around tossing basketsful of May flowers to each other either, and yes, their campaigns are full of borderline fouls and blurrings of the record. But Jimmy Carter, as before, seems to have few limits beyond which he will not go in the abuse of opponents and reconstruction of history.

The purpose of a campaign is to get elected. But a campaign can win at too great a cost. A campaign can be conducted in a way that casts doubt on the purposes and policies of an incumbent's own government and record. And a campaign can offend and turn off the very people the candidate expects to win, people who want to and normally would support him, if he is ruthless and reckless in seeking their vote. There must be a better case for his reelection than the one the president is now making.