No substance, please, we're television freaks. That was the message coming out of the clamorous aftermath of the historic nine-minute shout-out between Vice President Bush and CBS television anchorman Dan Rather. It was delivered by Ted Koppel, the magisterial maestro of ABC's "Nightline."

Former television correspondent Marvin Kalb was being difficult about the fine points of how Bush slew his wimpiness and came to be seen as a gladiator with his foot on the chest of a press lion. He persisted in noting that Bush's answers made no sense.

Koppel cut him off.

Later he was somewhat sheepish about it, explaining that Kalb was "getting too wrapped up . . . in the details," thereby nailing down the point he had originally made. He made it semi-official that we captives of television have become its slaves. What comes across on the box is the only reality. What people think of it is what counts. Hang the facts; perception is all.

We have long since known that a candidate's commercials can influence voters more than his speeches. The screening of America is now complete. Dan Rather has probably nominated the Republican candidate and may even have elected the next president.

What Bush actually said seems of little consequence. What matters is the reaction. Thousands of viewers who got through on the network's jammed lines have recorded their passionate conviction that Rather is a boor and a bully.

Actually, he was asking questions, and the vice president was ducking them. All who have seen "Broadcast News" know what Rather's problem was: The producer was pouring frantic alarms into his earpiece -- "Danny boy, wrap it. We're out of time. NOW." Rather's prosecutorial, pneumatic-drill interviewing style brought to roaring flames the ever-smoldering resentment of the news media, which is particularly strong in the right flank of the GOP.

Bush's opening complaint that he had no idea that the program would be dedicated to the Iran-contra scandal needs translation. It was hard not to know. The subject was advertised on "60 Minutes" the night before. CBS called the press to alert them to the showdown. What Bush meant was that he had no idea that the cogent lead-in material, which highlighted his multiple contradictions, would be so tough. But he knew what was coming. He tipped his hand when he aimed a nasty blow at Rather for his seven-minute walkoff from the news set.

The vice president gave his usual incoherent alibis, which never rise above the class of "the dog ate my homework." Perhaps the most damaging charge he makes against himself is that he can't remember Secretary of State George P. Shultz's vehement arguments against the arms-to-ayatollah scheme and so cannot be faulted for not having opposed it. In other words: "Who am I to just say no?"

In the midst of the international uproar over Rather's manners, President Reagan suddenly appeared on stage in a cameo, comic role. He was playing witness for the defense. Perhaps it was an act of kindness or perhaps the reflex of an old actor who has been upstaged. Reagan's State of the Union speech -- a mothy vaudeville turn, heavy with sight-gags -- went almost unremarked. Congress was buzzing about the new champ. Lawmakers gave Bush the lustiest applause he has ever heard in the House chamber when he entered a few minutes ahead of Reagan.

At any rate, Reagan announced emphatically that Bush was not at the meeting where Shultz exploded.

Here is a man who cannot recall whether he knew about the first shipment of TOW missiles to the ayatollah, which occurred in July 1986. First he told the Tower commission he did; then he said he didn't; he ended up saying he just couldn't remember. But Bush's absence from the circle considering the crack-brained idea was crystal clear to him.

Bush is swaggering through the countryside telling schoolchildren his encounter with Rather was "kind of like combat, you know."

Up until now, high school pupils in Iowa and New Hampshire have been putting sharp questions to him. They may stop. If they've been watching television and taking in the public fury against Rather and the acclaim for the vice president, they might think it is un-American to ask. But others will, particularly when the indictments start coming down and people are reminded that there is life away from the tube.

How could Bush lay away the scandal the way he flattened Rather? Says one Republican elder: "He should say, yes, I supported it, and it was the stupidest mistake of my life."

But he won't do that -- unless, of course, his media consultant tells him it would make good television.