SACRAMENTO — Known for battling carbon emissions, Californians are dealing with an environmental degradation of another kind this spring: pollution of the airwaves. Wave after wave of high octane, negative political advertisements have crowded out any hope of thoughtful discourse in the Republican gubernatorial primary, the outgrowth of an unprecedented $100 million poured into a tightly contested campaign by two wealthy masters of the Silicon Valley universe: Meg Whitman, billionaire ex-chief executive of eBay, and multimillionaire Steve Poizner, the state's insurance commissioner. "The more money you have, the more poison you can buy," said Jack Pitney, a government professor at...