In the curious alchemy of a national political campaign, what began as an embarrassing slip-up by Vice President Bush has turned into an unofficial rallying cry.

"Kick Ass George" posters have bloomed amid the forest of "Four More Years" and "Reagan-Bush 84" signs that await the vice president at every campaign stop.

Bush has taken to alluding gleefully in speeches to his now-famous, off-color remark -- such as when he apologized to the prestigious Commonwealth Club in San Francisco Wednesday for being tardy, explaining: "Barbara his wife and I were upstairs washing our mouths out with soap." That line, used several times this week, draws some of his loudest laughs.

His staff is now sporting " 'Kick Ass' George" buttons and passing them out to the traveling press corps with even more fondness than they exhibit for Reagan-Bush buttons. A source said Bush has commandeered a button of his own, but is keeping it out of sight.

This all began somewhat less auspiciously on the day after the televised debate with Democratic vice-presidential nominee Geraldine A. Ferraro when Bush, flush with a feeling of victory, crowed to a dockworker: "We tried to kick a little ass last night." At the time, Bush was visibly upset to learn that his blunt, whispered words had been taped, and he yelled at the holder of the offending boom microphone: "Turn that thing off!"

Now the tape of that encounter has been played for national television audiences, and the Reagan-Bush campaign is apparently so pleased with the response that it is producing "Kick Ass George" posters for the crowds assembled to meet Bush at GOP rallies and airport arrivals.

Ferraro, Bush's opponent and the target of his remark, has demanded an apology through her aides, but the vice president has said that it was nothing more than an old Texas football expression and that most people understood it that way.

On his travels this week in the battleground states of Oregon, Washington and California, the vice president has encountered little evidence to the contrary.

When he met with a group of farmers in a lush orange grove near Bakersfield, Calif., on Wednesday and mentioned the Ferraro debate, one farmer hollered: "That was a good line you had."

"Which one?" Bush asked, grinning.

Before the man could answer, Barbara Bush leaned into the microphone and said loudly enough to drown out what he planned to say: "Never mind!"

In San Francisco's Chinatown, as Bush toured curb-side food stands, sampling roast pig and Peking duck, a woman approached a reporter and said in broken English: "Kick ass George. Four more year."

All of this has delighted Bush's staff, which has been fending off suggestions throughout the campaign -- even from within the GOP -- that the vice president, with his patrician and "preppie" bearing, is not quite manly enough for voters' tastes. "I think it makes him seem a little more earthy," one staffer said.

Press secretary Peter Teeley predicted that "if Bush ever runs for president," as he is all but certain to do in 1988, his once-regretted remark will likely become his unofficial campaign slogan -- a 1988 version of "Give 'em Hell, Harry."

"If you've known George Bush for a long time, that's not something that would surprise you," Teeley said of his boss' remark. "George Bush is a real jock. He's very comfortable in the locker room. But I guess people who don't know him are a little surprised, especially hearing it from the vice president of the United States."