WHAT IS GOING ON around here? God knows, there have been, in the parlance, presidential "massacres" before. But Tuesday's mass resignations had, by Wednesday, got the sardonic observers and wise guys around town talking about a political Jonestown. There was (and continues to be) something distinctive about President Carter's crackdown - and the distinctions between it and your ordinary, ritual midterm massacre are worth considering.

Feeling obliged to show that he was in charge of things and also a stated yearning to be surrounded by "my guys," President Ford, of a Hallowe'en weekend - there was plenty of anxious rumor-trading then, too - fired and rearranged a whole slew of high officials, affecting both his Cabinet and White House staff. President Kennedy did a slightly less seismic, but somewhat comparable number about a year after his election. So let's start with the fact that, as the fellow said, everybody does it - or something vaguely like it, anyway. And let us quickly add that presidents can and should be free to arrange and rearrange their top-level appointees in the way they think works best for them. What then is to be made of what actually is going on?

A first conclusion is this: Some of Mr. Carter's moves are probably not only right, but also overdue. He should have a chief of staff and Hamilton Jordan as his senior trusted aide should be it. A more normally structured and less collegial White House staff (and atmosphere) is likely to improve the efficiency of the Carter presidency. So is the demise, if that's what it is, of that one-man, one-vote concept of management that the president appeared to favor and defend up until this week - his letting a hundred flowers bloom in his administration so that policy was dissipated, where you could locate it at all, and discipline was nil. People have been saying for a long time that this president seemed - in his amiable, almost indifferent, tolerance of public self-expression on the part of his appointees - to be squandering his authority. No one, it was noted, seemed afraid of him - even a little bit. If that has changed too, so much the better.

And there ends the good news., Now for the part that doesn't look so good. At the simple human level, this thing, with its wild and crazy "evaluation" form and its sudden icy change of mood and evident insensitivity to the feelings of those in government who had been overindulged before, is likely to have the demoralizing effect that sudden unkindnesses always do. More basically, the president doesn't much sound as though he remembers a couple of important things. One is that the reason presidents are generally conceded a very free hand in choosing and arranging their top-level assistants and Cabinet officials is that ultimately these people are agents of the president and he is responsible for what they do. So a 2 1/2-years-into-the-term revelation that things are going very badly implies, first, that the president has been far from attentive to his business and, second, that he - not just a bunch of others - has been derelict. Blaming disloyal appointees for the administration's troubles and himself only in the inference that he shouldn't have let them mess up his undertaking is an unpersuasive case, and one that is unlikely to do any better beyond the Potomac than it does right here in treacherous old Washington.

The other fact the president doesn't seem to have remembered is that all the shortcomings and flaws and malpractices he finds so disturbing among individuals in his administration represent forms of conduct he not only acquiesced in, but in some respects positively encouraged. And some of the reports of his sudden reaction against these ways don't sound like an assertion of authority so much as an explosion of pent-up frustration and rage.

Mr. Carter in his current and perhaps eternal anti-Washington mood may not believe it, but people in this much despised town are hoping that he will make a go of his administration. They want to believe the president has decided to summon the order and strength required to do the job and the rare courage to concede his own mistakes. And, being an unsentimental lot, they won't even mind all that much if a few large egos and ambitions get bruised along the way. That is why the unclear signals coming out from behind those closed doors are so disturbing. Listening to the hullabaloo you still can't tell whether the president is being big and tough or small and mean.