Looking for Mr. Nader : Politics: Voter Revolt populism is finished unless the consumer advocate boosts its latest brainchild.

It is gospel in California politics that without Ralph Nader’s imprimatur, Proposition 103 would have lost. Now, more than a year later, the consumer advocate is again desperately needed in the fight to reduce auto-insurance premiums. But will Nader ride to the rescue?

Proposition 103 author Harvey Rosenfield and his populist Voter Revolt organization, fed up with the legal wrangling over implementing his voter-approved insurance reform, recently introduced “Son of Proposition 103” (as yet the measure has no official title). Under the proposal, all private auto insurers would be expelled from California if, by Sept. 1, 1991, average insurance rates were not 20% below 1987 levels and if more than 15% of the state’s motorists were uninsured. A nonprofit state insurance company would fill the void.

Rosenfield and Voter Revolt need to collect a million signatures by May 18 to ensure that the measure gets on the November ballot. That’s a challenging task since both he and fellow reformer Bill Zimmerman couldn’t qualify an initiative that would have given taxpayers a sizeable rebate by shifting the Proposition 13 tax burden to business.

Trouble is that Nader has been crusading to limit the number of terms a politician can spend in Congress. He’s had no time to take a position on Son of 103.

Rosenfield insists that he would never embrace a cause that Nader didn’t support. Nader, he also points out, became active in insurance reform only after the Proposition 103 signature process was well under way.

Compounding Voter Revolt’s political problem is that only one of the major candidates in either party for the new post of elected insurance commissioner backs Son of 103. Conway Collis, a member of the state Board of Equalization and Voter Revolt’s major fund-raiser, has endorsed it. Not so former Common Cause director Walter Zelman and TV commentator Bill Press, neither of whom were strong Proposition 103 boosters.

Which make’s Nader’s role all the more important. Unless he actively backs Son of Proposition 103 early in the new year, Voter Revolt’s effect on state politics may prove to have been the equivalent of a meteor shower rather than a comet.

Although campaign reports will not become public until late January, it’s likely that Sen. Pete Wilson, virtually certain to be the GOP nominee, will have a cash edge over both his potential November gubernatorial foes, Atty. Gen. John Van de Kamp or former San Francisco Mayor Dianne Feinstein. The senator’s expected $4.5 million on hand may top the combined war chests of both.

Van de Kamp will have somewhere between $2.5 million and $3 million, depending on how much money he sinks into signature-qualification drives for his three initiatives aimed at the November ballot.

Feinstein’s war chest could hit about $1.5 million as a result of the seven-figure check she and her money-manager husband, Richard Blum, were expected to contribute to her campaign.