If only they had the cheek and daring of the original "Saturday Night Live" crowd, they would have opened the program by saying, "Live from Hymietown, it's 'Saturday Night'!" But the Rev. Jesse L. Jackson was treated mainly with rueful deference when he made his show biz debut Saturday as guest host of the NBC late-night comedy program.

Although paling in comparison to days of Belushi, Aykroyd, Chase, Radner, Newman, Murray, Curtin and Morris, the new "SNL" repertory company has more than its share of capable character actors who can slip into and out of roles and impersonations. What it doesn't have is a star-quality standout, however; nor does it have a single black regular in the cast.

On Saturday, both problems were solved for one night only. Jesse Jackson revitalized and energized "Saturday Night Live" with a performance that was sure, funny and accomplished. All those years in the pulpit were not for nothing. Jackson knows how to wow a crowd, one way or another. Early returns -- that is, ratings -- indicate the former Democratic presidential contender attracted larger audiences than are usual for the program in its post-hip era. The NBC switchboard also logged about three times the normal number of phone calls, the Associated Press reports.

An NBC spokesman said many of the callers complained that the show wasn't funny and was in bad taste. So what else is new?

Following in the guest-host footsteps of such other public citizens as George McGovern, Ralph Nader and Ron Nessen (who brought along filmed appearances by Gerald R. Ford), Jackson took the show by storm. He sang ("Red Rubber Ball"), danced a little, did an impression of George Bush as Reagan's Stepin Fetchit, told a joke (the anti-media "Jesse Can't Swim" joke he's told before), joined in a rap-song and, as the show's news anchor, analyzed the Reagan-Mondale debate.

More than once Jackson appeared to be ad-libbing lines or physical business, sometimes distracting his fellow actors. He reportedly wrote much of his own material. To say it was up to the show's usual standard would be much too insulting.

During Jackson's debate analysis he noted that Reagan had said some of the defense budget goes for "wardrobe." Jackson corrected him, "Wardrobe is for war movies; uniforms are for a war." And while a videotaped picture of Reagan groping for words appeared on the screen behind him, Jackson counted off seconds with his fingers.

There were no references to Jackson's infamous "Hymietown" remark nor to the often newsworthy antics of Jackson supporter Rev. Louis Farrakhan. This kind of thing was off-limits. In the precredit sketch, which began as a parody of the opening of "The Godfather," Jackson sought counsel on show biz comportment from Sammy Davis Jr. (regular Billy Crystal), who ended the sketch by saying "Live from New York, it's 'Saturday Night' " in Yiddish, a questionable touch under the circumstances.

The subject of anti-Semitic remarks was scrupulously avoided but hovered anyway; there were anti-Jackson pickets outside NBC studios at Rockefeller Center but these, of course, were not seen on the air. The touchiness of the topic might have been solved by putting Jackson on a panel with a make-believe George Bush and a make-believe Ronald Reagan and having them all participate in a lively edition of "What I Meant to Say."

In an opening monologue, delivered without a hitch or a stumble, Jackson said he agreed to guest-host the program because he "figured I had to get this last shot at America's mind." In sketches, he played the host of a game show called "The Question Is Moot"; amplified his comments on the "Rainbow Coalition" by noting that some people would be excluded from it, pluralism or no (the exceptions included "women who go shopping in tennis dresses," Dick Cavett and that actor in the Sylvania commercials who looks like Dick Cavett); and delivered an oration of mock adoration to U.N. Ambassador Jeane Kirkpatrick.

This little ode was supposed to be sarcastic but it just laid there.

In the most successful recurring bit on the show, Jackson would praise "Saturday Night Live" for hiring so many blacks for its staff, then wander into the control room where the white technicians, including director Dave Wilson, were scrambling for the doors so that black replacements could be rushed in and take their seats at the controls. Finally Jackson conceded that there weren't enough blacks on the show and urged funny blacks and Hispanics to write in and audition, a lame joke that fell flat.

It fell especially flat in view of the fact that with Eddie Murphy's departure at the end of last season, the "SNL" cast is now all white, and that's not so funny. On the previous week's program, two white actors in blackface played elderly black ball players.

Most of the political humor was anti-Reagan, suggesting that if they really wanted to, the Republicans could make some sort of equal time fuss with the FCC. But then they'd have to send a Republican guest host. Other than Robert Dole, there don't seem a whole lot of yuckety-yuck contenders. Republicans just aren't funny. They're about as funny as municipal bonds. Jackson was not only funny, he was astute, stalking out of an amusing but very silly airplane sketch to complain, "This is just dumb. This is stupid. This doesn't make sense."

Today, television stardom; tomorrow, television criticism! Either way, Jesse Jackson logged a socko performance and came off a fairly accommodating good sport.