Staging a major-party political convention is a lot like producing the Radio City Christmas Spectacular Starring the Rockettes. A million things can go wrong -- from bungled cues to attention-anesthetizing pacing -- but at least you can count on a big, high-kicking finale.

The producer of the convention that opened Monday night in Madison Square Garden knows from both Republicans and Rockettes. David J. Nash has staged five Republican National Conventions and about a zillion Christmas Spectaculars, some with live camels. And in his 68 years, Nash has learned one important lesson about putting on a spectacle: Above all, keep it moving.

Conventions, he readily acknowledges, can drag. That might be acceptable for a church service, but it is self-defeating for a political convention, a made-for-TV event that is the party's single best shot at promoting its candidates and its message. "All of us who work in TV understand that as soon as you hit a dead minute, people will hit the button and they're gone," says Nash, whose thick accent instantly betrays his New York roots.

Nash cannot control what TV audiences see hour after hour -- the networks have their own cameras and can pick their own shots -- but he is determined to put the best face on the raw material. He is in charge of knitting together all the elements -- the design of the sets, the speakers, the biographical video snippets, the musical acts -- into one smooth-flowing production. He compares the task to putting on a variety show, albeit one in which the stars talk about national security and tax reform.

Standing in the Ohio delegation's section on Sunday night, a cigar peeking out of his breast pocket, Nash surveyed the frantic preparations for Monday's opening night. "Wet Paint" signs were still hanging from railings in front of the podium, and throughout the hall power tools whined and screeched. The whole arena smelled of new carpet -- acres of bright Republican-red carpet that, while hard on the naked eye, is sure to pop off the TV screen.

Nash has produced everything from Kennedy Center Honors shows (he was once technical director at the center) to Dolly Parton TV specials to the 1986 centennial of the Statue of Liberty. He was the number two producer of the Democratic convention in 1988 but switched sides in 1992, running every Republican convention since (he votes Republican, too).

Nash will spend a good part of this week ensconced in the convention's equivalent of a bunker. He will direct all of the stage action and a crew of about 200 from underneath the podium, where a thrumming, high-tech mini-city has been built to serve the production.

The center of attention will be directly above him, on the large but relatively simple stage. Breaking with custom, Nash sought something stripped down, hoping to avoid the hulking "battleship look" that Democrats and Republicans alike have used for years. There are, of course, the usual towering Jumbotron video screens (which can pump out 430 different images, from rippling American flags to racing-car graphics). But the stage's open, trapezoidal design is intended to convey simplicity and accessibility.

"I thought the Democratic convention [in Boston last month] looked good -- and by good, I mean good for their purposes," Nash said. "We don't really need to demonstrate to viewers that President Bush is presidential. Everyone knows that. But when you're the challenger, it's important that the candidate be in a setting that makes him look presidential."

This idea will get an almost radical, off-Broadway spin on Thursday, when Bush accepts his nomination. The president's speech -- sure to be the most watched moment of the convention -- will take place on a small, circular stage surrounded by the seated delegates (the main stage will be dismantled and the new setup built overnight on Wednesday). The in-the-round format ensures some unusual camera angles. Even more important, the party is hoping for flattering symbolism: Bush, close enough to touch, boldly going among the people, speaking intimately. "This is part of an effort to bring the president out of the hall and into people's living rooms," says Christine Iverson, a spokeswoman for the Republican National Committee.

Viewers will see one other innovation in design and theatrics. The orchestra pit -- or, as organizers call it, the entertainment stage -- really is a pit, but with a difference. It is sunk deep into the arena's floor, which is itself a temporary surface built 91/2 feet above the Garden's actual floor. The entertainment stage is built on hydraulic lifts so that musical acts can be raised and lowered in less than 30 seconds.

Although it may be neat to watch, say, Brooks & Dunn or the the Boys Choir of Harlem rising from out of nowhere, the real goal is to minimize distraction and downtime. "For some reason," Nash said, "people are fascinated by seeing someone set up a drum kit. This allows us to move people on and off without taking a break, and without losing the delegates' attention."

That is the best he can hope for. Nash cannot control the political message, or make the speakers seem brighter or livelier. All he asks for is "a clean show that serves the people and the party."

"If we can do that," he said, "we'll have been successful."

Actually, he really would have liked one other thing: fireworks. Nash was hoping to shoot off sparklers during the convention's inevitable balloon-drop finale, but security nixed the grand climax. Maybe the Rockettes are still available.

David J. Nash has produced five Republican National Conventions and many Radio City Christmas Spectaculars.