What a chore to tear oneself away from "Aliens" on HBO for "Democrats" on PBS. But it turns out the Democrats were a good show, too, if not precisely a hair-raising thriller.

William F. Buckley Jr. invited the seven most likely Democratic presidential contenders to join him in Houston Wednesday night for a "Firing Line Special." Buckley, the gourmet conservative, announced that the program would be "unsparingly partisan but scrupulously fair" and had asked "Mr. Democrat," former party chairman Robert Strauss, to cohost.

The structure was looser and more productive than the rigid League of Women Voters debates that precede elections.

Surely only our hardiest pundits are already in a 1988 election mood. But the program offered enlightening glimpses of the Democratic hopefuls, enough to afford a preliminary fix not so much on what kind of president each would make as on what kind of campaigner each will make. And how great a communicator. Everyone knows how important that is.

The bright new star to emerge was Sen. Paul Simon of Illinois, who is also the most unassuming of the bunch. He seemed level headed, forthright and peppery -- as effortlessly folksy as Orville Redenbacher and, best of all, bracingly Trumanesque. Ronald Reagan never tired of comparing himself to FDR; maybe Simon could succeed Reagan as Truman succeeded Roosevelt. Maybe the country will want to go from head in the clouds to feet on the ground.

True, Simon looks a bit like Oscar Levant. He has oddly floppy earlobes. But these flaws are more like endearing badges of honor; Simon's neither simple nor synthetic. "If you want a slick, packaged product, I'm not your candidate," he said, stating the obvious and vowing to continue wearing those quaint bow ties no matter what.

Simon, who has such a rich baritone that he could be the announcer for the Metropolitan Opera broadcasts, is the most engaging new eccentric to hit television since Alf. Not Alf Landon; Alf the extraterrestrial.

Bruce Babbitt, the former Arizona governor, has a touch of Jimmy Stewart about him, but he also has a touch of Jimmy Carter -- the lines in his face bring back Carter memories one doesn't want brought back -- and parading around in flannel shirts (each candidate was allowed to bring a 90-second taped autobiography) doesn't help.

Jesse Jackson, who has sought the office before, obviously has a tremendous oratorical advantage over other contenders. He was the only candidate on the Buckley show to rise for his final summation. Jackson was so eager to prove a grasp of foreign affairs that he may have slighted domestic matters. He definitely had the most fashionable lapels.

After Jackson prescribed medicine for America's horrendous trade imbalance, Buckley grinned and said, "I happen to agree, but I don't want to embarrass you." Ah, Bill, ever the sly boots. And sometimes the Cheshire rat.

Richard A. Gephardt, representative from Missouri, appeared rather wimpish and ineffectual. He casts a fuzzy shadow. When Buckley, as the first question of the night, asked each candidate to say which presidential portraits he'd post in the Oval Office, Gephardt was a poor sport and wouldn't play along, saying "the real issue" was blah blah blah and declaring he'd put the Constitution on the wall. A copy, presumably.

Couldn't he have just answered the darn question? At least Gephardt did have the guts to say, on the subject of a balanced budget, "What Ronald Reagan needs is guts."

Michael S. Dukakis, the Massachusetts governor, has a pleasing, cushioned television manner, very relaxed and conversational and, alas, not very exciting. Television calls for a politician to be easygoing and electrifying at the same time. It calls for that mainly because Ronald Reagan, in his prime, anyway, was able to do it.

Albert Gore, senator from Tennessee, reinforced his image as a plain, dull square. He looks like Clark Kent -- but a Clark Kent who would never dream of undressing in a phone booth. Nor perhaps anywhere else. Having a wife who sniffs out naughty rock lyrics hardly mitigates the impression. Gore opens his mouth and one feels a snooze coming on. But he was good sparring with, and getting the best of, Buckley during a tiff over "Star Wars" experts and projected costs.

Finally there is Joseph R. Biden Jr., senator from Delaware, and famous George Shultz tongue-lasher. Biden seems bright, tough and bold. Also very, very scary. One might even say terrifying. He has Rod Serling's upper lip, which is no shortcoming, but suggests maybe he should only be president of the Twilight Zone.

Like Gephardt, Biden refused to play along with Buckley's harmless, colorful opening question. The candidate appears to be overadvised and suffering from excessive consultitis. Worse, he comes across on TV as someone whose fuse is always lit. Unless we ditch television for the remainder of the campaign, Biden will never be president.

Except for some sluggish camera work, the program ran smoothly, but someone should have handed Buckley a cough drop, because he began the program loudly clearing his throat and kept that up through all two hours. Apparently he was ill. But a viewer might have interpreted all the noisy throat clearing as an intrusive rhetorical trick. Maybe Bill has been spending too much time out on the bounding main aboard his yacht.

He gingerly avoided asking the candidates for their reaction to Reagan's announcement of Judge Robert H. Bork to fill a Supreme Court vacancy. By repeatedly anticipating "Reagan-bashing" and the "torturing and dismembering of Ronald Reagan," Buckley tried to make the Democrats look as though they were being mean to the old boy, but there was no meanness at all.

Perhaps, actually, it's time for some.

Buckley's adversarial posture was probably helpful. It kept the candidates on the alert and helped prevent doldrums. Nearly everyone may be dreading the long campaign year ahead, but this "Firing Line Special," produced and directed by Warren Steibel, got it off to a promising start. It said to the viewing electorate, "Maybe this won't be as bad as you think."

It also indicated that maybe it's the other Paul Simon who will soon be known as "the other Paul Simon."