The first edition of "ABC News Nightline," two years ago, was something of a mess -- the program jelled into its current format, and excellence, later -- so maybe it shouldn't distress anyone at ABC News that Tuesday's premiere of the new post-"Nightline" show, "The Last Word," came off as a souped-up, slipshod, great big gust of uselessness.

"The Last Word" was hardly ne plus ultra in television news; it was hardly television news at all. The program should be allowed a chance to improve, but there's reason to doubt if the chemistry will ever be quite right between the show's two hosts, stuffy Greg Jackson and that old incendiary Phil Donahue. There hasn't been a split personality like "Last Word's" since Dr. Jekyll and Mr. Hyde, except that the way these partners operated on the first program, it was more like Mr. Hyde and Mr. Hyde. They were both monsters, but with different personalities.

Jackson seemed slow, tongue-tied and fog-bound in his interview segments from New York. Donahue, in pre-taped, edited sessions from Chicago, outdid himself at interrupting and leaping at guests, and at desperately trying to keep the discussion heated to the boiling point every single moment. He more than earned the nickname of Phil Donnybrook with this shamelessly hammy performance.

The program's principal gimmick is its ability to accept phone-in questions from viewers via a special 800 number that is flashed onto the screen. This radio staple is not a television first for ABC; PBS has been doing it for some time on the "PBS Late Night" show (now seen here nightly at 11:30 on Channel 32). For the record, ABC News said yesterday that the switchboard was jammed with 1,200 calls, its capacity, within one minute of opening up the lines, although only a handful were used on the air.

Donahue's segments on the one-hour show were devoted to the phenomenon of Political Action Committees (PACs) and their influence on politicians. For this, Donahue needed four guest experts and a studio audience, all the better to generate Donahue's peculiar brand of snappy-crackly colloquy. When Donahue wasn't interrupting the guests, they were interrupting each other, and Donahue loves that sort of thing. He likes to have guests fighting for the floor. If the talk show racket ever bottoms out, Donahue can always turn to refereeing at cockfights.

His rabble-rousing approach works fine on the hour-long, daytime, syndicated "Donahue" show, but at midnight, and with the added pressure of less time in which to whip up frenzies, it just seems loud, rude and unproductive. The one nice touch was when Donahue unfurled a computer printout listing contributions to the top five Senate beneficiaries of PAC generosity. "Pardon the theatrics here, but we want to make a point," said Donahue as the paper snaked through the crowd.

Of course, if Donahue said "Pardon the theatrics" every time he got theatrical, he'd do almost nothing but apologize. But the use of the computer printout was emphatic and graphic, and a visual relief from all the yammering.

ABC cunningly held off the first commercial break until 11 minutes into the show, but after that, the program was interrupted by a steady blitz of annoying ads. Some segments were only three or four minutes long; then, back to the old pitcheroo. A mere 44 minutes of the show's hour are devoted to program material.

If Donahue's segments were banzai interviewing, Jackson's portions were soporific ringers. Halfway into the program, he conducted a transcontinental interview with two convicts live from San Quentin, the point of which was ostensibly to give viewers advice on burglar-proofing from two real burglars. But the only counsel that evolved was the common-sense household hint surely everyone knows by now: you should keep the lights on in your house and notify neighbors when you're going away for a few days.

Jackson's technique is trapped somewhere between the disingenuous and the oblique. If he found burglars in his house, he asked the men, "What should I do? Should I try to chase them away?" One convict responded, "Burglars normally don't have a tendency to want to be identified." How's that for a piece of news? But Jackson got sillier. "Am I right in being afraid of you two?" he asked.

That question produced a choice response from one of the convicts, who seemed aching to be taken for a cultural stereotype. "I think sensationalism has made you frightened of burglars," he told Jackson. "Burglaries are part of society today from the time your children watch cartoons on TV to 'Mission: Impossible' to, let's say, 'It Takes A Thief' to your local private eye program. They all portray acts of burglary."

Clearly, this is one thief who has spent too much time watching Phil Donahue shows.

At the end of the program, Jackson incongruously burbled, "Listen, it's been fun; those inmates in San Quentin were fascinating." Right, Greg! Let's drop in on them again real soon. Perhaps the ratings on "World News Tonight" would pick up if Frank Reynolds would say to Max Robinson at the close, "Listen, it's been fun." Don't rule it out.

Before the kiss-off farewell, Donahue popped up again with another Chicago segment, a non sequitur that had him asking a small crowd in a studio whether "our schools" should dispense Bibles to children. One woman said, "Don't we in the United States say 'In God We Trust'? We don't trust in Buddha."

It was all uphill from there -- just a few more commercials and a nighty-night. But for "The Last Word," it was all downhill from the close of "Nightline," when poor Ted Koppel was called upon to play the house shill and the house shmoo with all-too-typical ABC News promotional zeal, introducing the new show and giving it a big fat cross-plug. A promo for "20/20" was thrown in there, too, with an announcer bellowing, "The hidden shame of incest! Then, Geraldo Rivera crosses the border with illegal aliens!"

Listen, it's been fun, but also, as "The Last Word" now stands, a complete waste of time.