IS HE or isn't he a candidate? How can you tell, until Sen. Edward Kennedy tells the world himself? He certainly has not been shrinking from public platforms or making Shermanesque statements recently. Nor has he told those mushrooming "draft-Kennedy" committees to disband. On the other hand, he has formally disavowed their activities and has not authorized any committee to raise money or campaign on his behalf.

So he has neither closed the door nor crossed the legal threshold into candidacy. Does it matter what you call his current stance? You bet it does. The campaign "reform" law, in one of its more consequential quirks, makes free-lance promotion of draftees and non-declarers easier than orderly, coordinated campaigning for someone who has at least agreed to let his cause be advanced. The dollar difference is considerable. Under Federal Election Commission rulings, as long as the draft committees are not affiliated with Sen. Kennedy, individuals may contribute up to $5,000 to any one of them and up to $25,000 to the efforts overall. Individuals' gifts to the Carter campaign committee, just for an example, are limited to $1,000. That's not all. As long as the draft-Kennedy operations manage to stay at arms' length from each other, political action groups may give up to $5,000 to each one; if they got together, a PAC could donate only $5,000 overall. Finally, unaffiliated groups are not held to the state-by-state spending limits that candidates must observe.

It's a ludicrous situation. Besides putting President Carter at a disadvantage, on top of his other political woes, the rules encourage all of the shadow-boxing and legal dodging, that may be time-honored political sport but which make controls a farce. No wonder Mr. Carter's agents are reportedly preparing to challenge the FEC's ruling. The appeal should be addressed to Congress, though, because this is one regulatory snarl that the FEC did not create and has, in fact, been begging Congress to straighten out ever since the 1976 campaign, when similar questions about other near-candidacies arose.

So far, of course, Congress has carefully avoided acknowledging most of the problems it caused by trying to impose finely sliced limits and distinctions on political activities that, by nature, are incurably muddled and shadowy. But perhaps there's some hope. Both houses are finally moving to resolve a related problem, by easing restrictions that inadvertently put such a damper on grass-roots volunteer efforts and local support-the-whole-ticket campaigns in the 1976 Carter-Ford race. The next job is to make the rules treat all campaign groups more equally, whether their candidates are candidates or not.