From the warm, soothing comfort of his bathtub, Howard Jarvis started campaigning Tuesday with a wire service phone interview shortly after dawn. He ended nearly 20 hours and a hundred mild obscenities later, still preaching his anti-tax message over one of this city's late night radio talk shows.

In between, Howard Jarvis, 75, tireless crusader, managed to shake the foundation of California's mammoth state government and, as the author of revolutionary Proposition 13, he emerged as a symbol for people who fear that the government seeks to tax them out of their homes.

"People don't know the b . . . s we've been electing. They didn't know they elected people who were evil, 90 percent immoral," Jarvis growled, his paunch sticking out of his plain white shirt as he paced around his modest, immaculately clean home. "They want to take everything we have - but now we're giving them an enema."

On Tuesday night, through passage of Proposition 13, a measure drastically limiting property taxes, Jarvis and millions of servants from Gov. Edmund G. Brown Jr. to the local dogcatcher on a very tight leash.

For years they laughed at Howard Jarvis, calling him an amusing gadfly, a kook, a quait, ranting old man.

But, today, at an age when most men seek the quiet oblivion of retirement, he has just reached his zenith.

It took 15 years of campaigning. With almost fanatic dedication, Jarvis threw himself into scores of lost causes - ballot measures, candidacies, petition drives - all with the single goal of curbing property taxes. For years the same voters who today love him rejected his bids for office ranging from U.S. senator to county assessor.

"When you start something good, people don't understand - they think you're crazy," Jarvis said hours after the polls closed, his eyes nearly shut with exhaustion. "They said Edison was crazy, out there playing with a bunch of string, but he invented the electric light."

Skyrocketing property tax bills have hit California homeowners hard in recent years. But many here, both for and against Proposition 13, say Jarvis determination, gutsy debating style and irascible although thoroughly enjoyable personality made the difference.

Jarvis' critics see him as a clever lobbyist for his clients, the Apartement Association of Los Angeles, apartment house owners who are sure to save money due to the passage of 13. But they admit that Jarvis' forceful personality howled over the anti-13 campaigh, setting the stage for passage.

"He's better theater than anyone we have," admits Gray Davis, campaign manager for Gov. Brown, perhaps 13's most powerful foe. "He seemed to be ableto tap the whole syndrome. He typifies the anger of these property owners because he's one of them."

So great is Jarvis' personal appeal that even some members of public employe unions - among his favorite targets in the campaign - could not resist voting for his initiative. "He came across like Sam Ervin , folksy, cutesy and all that, and he chewed our people up," said one embittered union leader."He came across backwoods and honest, and because of it we're stuck trying to figure out whose job we can save."

As early returns Tuesday night showed Proposition 13 way ahead. Jarvis supporters mingled quietly at their Biltmore headquarters downtown. There were matrons with tanned wrinkles, insurance agents with pot bellies and cowboy hats, youthful clean-cut families, elderly couples - all sedate and well-behaved.

Then, suddenly, there was a roar, a screech, even a few rebel yells. Peeking over the podium was Howard Jarvis, out there before the national television lights, swinging a gnarled fist. For 20 minutes the crowd went wild. When they finally cooled down, Jarvis poked his head at the camera and issued his warning.

"Now we know how it felt when they dumped English tea in Boston Harbor. We are seeing the beginning of a new American revolution," Jarvis shouted into the microphone, as politicians shoved their way to the podium to be near him.

To questions about his perseverance through so many defeats, Jarvis barks to his upbringing on a Mormon farm. "In Magna, Utah." he recalls with a broad grin, "the town I grew up in the only government we had was one post saying you were both entering and leaving town. That's what they should do to Washington D.C."