Remember when off-again presidential candidate Ross Perot told supporters to give the "rehabilitated" Democratic Party a chance in the summer of 1992? Now he's urging the remnants of his grass-roots United We Stand America to back the Republicans. "I have a simple proposal for the American people," Perot said last night on his favorite platform, CNN's "Larry King Live." All they have to do, he said, is vote only G.O.P. in November's House and Senate races, then let a Republican Congress drive for a few years. Idle chatter? TIME Washington contributor Laurence I. Barrett says the Perot movement's activists are already poised to boost Republican candidates -- with or without Perot's advice. Though they number just a few thousand, Barrett says, they may swing several House races where voter turnouts often dwindle below 35 percent: "These people take politics very seriously," says Barrett, "and if they've got a grudge against somebody, this can count."