Flipping channels late Tuesday night, the last thing I remember was a report that Pat Robertson's Iowa ''bounce'' had taken a bad hop in New Hampshire -- but no matter. He would roll through the South and fetch up at the Republican convention as a powerful force to be reckoned with -- at which point I must have nodded off.

Suddenly it's Jan. 21, 1989; intelligence analysts are briefing President Pat Robertson on the Middle East: a fragile ''peace process'' is in place, he is told. Israel confronts worsening internal troubles in the occupied territories; an international conference is at work on a settlement of the Palestinian conflict. With an air of patient indulgence, a smiling Robertson interrupts:

''Israel . . . will be invaded by a confederation from the north and east. The prophet Ezekiel described this force as massive, coming like a storm, a cloud covering the land. He identified elements of it as 'Gog of the land of Magog,' the 'prince of Rosh, Meshech and Tubal,' joined by Persia, Ethiopia and 'Put,' along with 'Gomer,' 'Bethtogarmah from the remote parts of the north' and 'many peoples.' . . . Indications are that this great power from the north may be the Soviet Union.''

But, sir, an intelligence expert replies, our evidence indicates that Soviets don't want a confrontation in the Middle East. ''The Bible says that . . . the Soviet Union is going to make a move against this little nation known as Israel,'' Robertson responds. ''Does the Bible specifically tell us what is going to happen in the future?'' he is asked. ''It sure does,'' President Pat replies. ''It specifically, clearly, unequivocally {says} . . . that Russia and other countries will enter into war and God will destroy Russia through earthquakes, volcanoes, etc.''

If you're thinking it might have been something I ate, this nightmare derived from something I read: everything in quotation marks above was extracted from Robertson's two books and countless ''700 Club'' TV broadcasts or newspaper and magazine interviews -- some as recently as last year and all within the past six years.

There's more -- much more -- of the same. But the point does not need laboring: instead of bridling when he is called a ''TV evangelist,'' Pat Robertson ought to be counting his blessings that he has not long since been laughed off the political scene for talking geo-Biblical gibberish. Instead, he was taken seriously enough in that most self-conscious of political exercises, the Iowa caucuses, to beat out Vice President Bush handily for second place.

What does this tell us? Something heavy, I suppose, about the American psyche: a reversion against the materialism of the welfare state, some sociopolitical authorities argue, accounts for a revival of religious fundamentalism, which, in turn, accounts in some part for Robertson's success. But surely another part of it has to do with the kid-gloves treatment Robertson gets.

True, the news hounds on the hustings are beginning to pick up, gingerly, on Robertson's politico-religious idiosyncrasies -- though rarely when it comes to the question of how his handling of war-or-peace, life-and-death national security questions would be dictated from On High. Whatever damage was done in New Hampshire by his weird visions of Soviet nuclear weapons in Cuba was self-inflicted.

In any event, the most telling challenge to Robertson's beliefs would have to come from his opponents. Here we arrive at a large part of the reason that he's been getting a free ride: pure and simple political expediency. Bob Dole's approach is illustrative. Robertson is trying to ''shed'' his past, says Dole, tenderly: ''Much of the past rhetoric has gone overboard.'' Besides, by his evangelical appeal, Robertson is ''broadening the base of the party.''

Now that makes sense, short-run, the more so if, as estimated, the strongest single bloc of Republican voters in the 1986 off-year elections consisted of fundamentalist Protestants. But expediency has its price for the longer run. If Robertson's swelling flock is to be a pivotal addition to the Republican herd, attention will have to be paid to it by convention programmers and platform writers -- and, beyond that, by GOP candidates. The greater the impress of Robertson on the Republican Party, the wider the party is likely to be carried to the right of even the conservative mainstream.

Republicans, in other words, would be turning back from the latter-day Reagan of arms control treaties and U.S.-Soviet summitry to the early Reagan ''evil empire'' theory of the case -- or to Robertson's: ''There has never been a force in the history of the world that has been as vicious, as malevolent . . .'' Without Ronald Reagan, ideological retrogression on such a scale could be a heavy burden for the Republicans in the fall.