ROSS PEROT is staging an all-you-can-eat political buffet this week that is unusual in American history.
It will bring together prominent politicians from both parties to address a three-day conference hosted by a group that could become a third party - United We Stand America (UWSA), Mr. Perot's watchdog organization.
For Democrats and Republicans, the conclave starting tomorrow is a high-stakes opportunity to woo voters they see as a crucial swing vote.
For individual GOP presidential hopefuls, it will be a chance to try to distinguish themselves from each other - and see if anyone can gain on the frontrunner, Sen. Bob Dole (R) of Kansas.
''The fact that the Republicans are all coming indicates that they feel they have more to gain,'' says Al Tuchfarber, an Ohio pollster.
Variety spices the schedule. The Rev. Jesse Jackson, a prominent liberal, will find his address on opportunity in America sandwiched between that of Republican Sen. Pete Domenici on balancing the federal budget and one on Social Security reform by Pete Peterson, co-founder of the Concord Coalition, a fiscal watchdog group.
Many politicians will linger at exhibit booths to shake hands and hawk their latest books. But the conference may seem less like a bazaar than a beauty pageant, with 10 declared Republican presidential candidates strutting in the spotlight.
Among their number is Texas's own Sen. Phil Gramm (R). He will hope to shine in the city where he set the world-record for fundraising in February. At that event Senator Gramm quipped that ready money was the best friend to have in Washington. But it hasn't helped him much outside the Washington beltway in his uphill quest to catch Mr. Dole.
For the two parties, attracting Perot followers will be critical in 1996, though both could be spurned should UWSA members form their own party or urge the Texas billionaire to repeat his 1992 independent presidential bid.
GOP consultant Eddy Mahe says Republicans will try to keep the allegiance of ''Reagan Democrats,'' the voters he says abandoned George Bush for Perot in 1992, and who last year helped Republicans seize control of Congress.
Such voters tend to be more protectionist than Republicans, and closer to the Libertarian Party view on social issues. That's the risk in subjecting them to a stream of free-trading, abortion-denouncing GOP officials, Mr. Mahe says.
Republican speakers, he believes, would actually be helped if President Clinton were part of the program because of the contrast that would create. The White House is sending presidential counselor Mack McLarty.
Risk for Clinton
The risk of coming personally would be too great for President Clinton, Mr. Tuchfarber says. He recalls how Perot invited representatives of both the Bush and Clinton campaigns to Dallas a month before the 1992 election to make their pitches for the support of the Dallas businessman and his followers. Declaring both to be inadequate, Perot immediately rejoined the race.
It would be devastating to Clinton, a sitting president, if the UWSA members he had just addressed were to form a third party or support an independent candidate, Tuchfarber says. The impact on the 10 Republican candidates in attendance would be less dramatic ''They've got a whole cast of characters, he says.''
''I would just hope there wouldn't be a third-party candidacy'' resulting from the conference, says Tom Pauken, chairman of the Republican Party of Texas. ''If the contest is between the GOP and Clinton, we win.''
Perot has not yet divulged whether he will repeat his 1992 independent presidential bid, which earned 19 percent of the vote and spawned UWSA. But he recently said that making the two-party system work would get results faster than forming a third party.
Robert Stein, a political scientist at Rice University in Houston, believes Clinton is passing up an opportunity. The president could score points on style without taking hits on policy, he says.
''The Republicans got where they are by being [linguistic] bomb-throwers,'' Professor Stein says. But politicians have discovered that shrillness alienates a public awakened to its dangers by the Oklahoma City bombing.
Exactly whom will these speakers address? UWSA is counting on its state chapters to fill conference seats. Members in the Pacific Northwest organized a sort of Oregon Trail in reverse. Four of five hotels booked by UWSA have been filled.
Perot has volunteered to waive the admission fee for Dallas-area residents who cannot afford it and for college students and professors, teachers, firemen, policemen, nurses, medical technicians, or retirees. Neither Republicans, Democrats, nor special interest groups admit any plans to pack the house with their own people.
UWSA spokeswoman Sharon Holman says ''We'll have all the space we'll need'' in the Dallas Convention Center's 9,000-seat arena.