As we saw last year, the flag issue seems to bring out the worst in certain eminent Republicans. For political apparatchik Ed Rollins, something like tampering with the First Amendment to prohibit flag burning is no more than a routine exercise in politics. The Democrats, says Rollins, ''are definitely not going to get a free ride on this.'' To him, the issue may be as useful to Republican House candidates this fall as the ''ACLU issue'' was to George Bush in 1988. That's about all you expect from a political hack. But what about Bob Dole? The usually serious Senate minority leader thinks that a vote against a constitutional amendment ''would make a good 30-second {campaign} spot.''

There are, of course, distinguished constitutionalists -- Judge Robert Bork is one, Justice Stevens is another, and there are others -- who insist that flag-burning is a form of conduct -- and bad conduct at that. It is, they claim, like painting a swastika on a synagogue wall and may be outlawed and punished as behavior. The First Amendment, in their view, doesn't apply.

Maybe it would have been better for the court to adopt that view last year and let this sleeping superpatriotic dog lie. But it didn't. One reason it didn't, perhaps, was that the Texas Court of Criminal Appeals had already produced a compelling argument to rule exactly as it did, holding that flag burning in clear political settings is a protected form of free expression.

''Recognizing that the right to differ is the centerpiece of First Amendment freedoms,'' said the Texas court, ''a government cannot mandate by fiat a feeling of unity.'' That is the major premise, difficult to dispute. ''Therefore,'' the Lone Star judges continued, ''{that government} cannot carve out a symbol of unity and prescribe a set of approved messages to be associated with that symbol.'' This was the minor premise, and it seems equally sound.

Which is to say that popular feeling about the symbolic meaning or significance of the national flag -- hence about what treatment it is due in any given setting -- must be voluntary. Otherwise, to the extent that ''suitable'' attitudes about the flag are forced on us by law, they violate precisely the cherished political values (personal freedom of thought foremost) that the flag symbolizes. It is idolatry, though in the case of the flag a form of secular idolatry, to mistake symbols for substance. And it is petty tyranny to require reverence for flags.

The First Amendment, it is no exaggeration to say, is the world's most envied and effective charter of free utterance. Amending it merely to reverse the court on flag burning might not do fatal injury. But it would set a risky precedent. Everyone has his pet dislike among the more unusual and exotic forms of expression that pass for free speech. Once the barrier is broken and the parade of exceptions begins, where does it stop? When the First Amendment, like a weird Swiss cheese imagined by Lewis Carroll, finally becomes all holes and no cheese?