Michael Dukakis, notes George Bush with disdain, is "a card-carrying member of the ACLU." And what is wrong with that? Campaigning in Texas, Bush explained that the American Civil Liberties Union is "pretty far out in left field" and does not reflect "Texas values." Campaigning in Kentucky, he declared that the ACLU "is not exactly in the mainstream of Kentucky politics" because it is composed of "liberals" who get criminals off on technicalities.

I wonder if Bush would apply this analysis to the ACLU's latest cause: Oliver North. The organization has filed a brief arguing that criminal charges against North and his Iran-contra colleagues should be dropped. Reason: North's Fifth Amendment right against self-incrimination was hopelessly compromised when he was forced to testify against his will in congressional hearings a year ago. Bush has been eager to wrap himself in North's popularity, when convenient. Is this one of the loopholes, and is Ollie one of the criminals, Bush is referring to?

In order to prevent North, John Poindexter and Albert Hakim from pleading the Fifth Amendment and refusing to testify at last year's hearings, Congress gave them what is called "use immunity." That means nothing they said could be used in any future prosecution. The alternative is called "transactional immunity," meaning that you can't be prosecuted at all for any crime you testify about.

Use immunity in federal prosecutions is authorized by the Omnibus Crime Control and Safe Streets Act of 1968. That act, a conservative response to the turmoil of the 1960s, was supposed to correct a grab bag of exactly the sort of liberal excesses Bush complains of. Use immunity was intended as a way to get a criminal's testimony against his colleagues without having to let him go free.

Iran-contra special prosecutor Lawrence Walsh and his staff went to enormous lengths to ensure that their prosecution does not use any "immunized" testimony. They put "under seal" all the evidence they had accumulated before North et al. testified, to prove it's not tainted. They kept detailed records of how they acquired each new piece of evidence. During the testimony itself, they stopped reading the newspapers and watching TV.

North's lawyers and the ACLU argue that in a case so widely publicized that it has become "part of American folklore" such steps are insufficient. Despite their best efforts, prosecutors can't possibly have avoided exposure to what North and the others said, and can't possibly prove that this didn't affect any decision they made. Nor can they prove that witnesses and jurors weren't affected.

Walsh argues that what prosecutors, witnesses and jurors may incidentally have learned is irrelevant. What matters is what they use. In all criminal cases, witnesses are sworn to testify only from personal knowledge, and this one's no different. As for jurors (although Walsh didn't put it this way), there's never a shortage in America of people amazingly ignorant of the most important public affairs.

District Judge Gerhard Gesell ruled for Walsh, though he said the question could be reviewed again after any conviction. For myself, I'm glad I'm not a judge because I just can't decide. It's certainly clear that whatever tiny advantage the prosecutors may have gained from the testimony is far outweighed by the disadvantage of all the knots they tied themselves into while trying to avoid being influenced.

But the point for Ollie North fans like George Bush to keep in mind is that this dispute is over presumably accurate and presumably incriminating information. That's what the Fifth Amendment protects. An American criminal trial is less a venue of truth-seeking than it is an elaborate game in which the truth is only one consideration.

And the game is never more elaborate than when in the hands of someone like North's lawyer, Brendan Sullivan. The Fifth Amendment question alone has already generated a foot of documents. And this is only one of many promising avenues of delay and obfuscation defense lawyers are pursuing. Sullivan's mentor, Edward Bennett Williams, once remarked puckishly that the right to a speedy trial is the least-exercised right in the Constitution.

No other country in the world would give Oliver North so many opportunities to "get off on technicalities" that have nothing to do with whether he broke the law. If the North prosecution is thrown out on Fifth Amendment grounds, people like me will find it terribly frustrating that the Constitution should rescue someone who clearly holds its values in contempt. But we will also recognize that it is one of the glories of America that it allows such things to happen. And we'll recognize that the American Civil Liberties Union is helping to protect that glory. Even if we think that in this case or some other the ACLU goes too far, we're glad to have it around because we know that zealots keep the rest of us honest.

George Bush, by contrast, would like us to believe that there is something un-Texan, un-Kentuckyan -- you know what he's trying to say -- downright un-American about the zealous, even excessive, concern for individual rights.