California: Democrats meddling in GOP race, Whitman campaign says

The group, Level The Playing Field 2010, released the radio ad Tuesday that directly attacks Whitman for planning to spend her personal fortune to win the governorship.

"She's threatening to spend one hundred and fifty million dollars to crown herself governor," a woman's voice intones.

The ad, and where it was placed -- stations that cater to conservative listeners -- convinced Whitman's campaign that Brown's supporters are trying to pick sides in the GOP primary.

"Clearly, there is a focus on Republicans as they purchased stations with the following programming: Rush Limbaugh, Sean Hannity, Mark Levin, and Glenn Beck," said an analysis by Whitman consultant Kyle Roberts, of Smart Media Group. "Any savvy media observer would conclude this campaign is designed to target and persuade Republicans during their primary election."

Level The Playing Field 2010 is one of three independent groups that have pledged to raise upward of $40 million to help counter Whitman's message -- which until now has been unanswered on the airwaves. Groups independent of campaigns can raise and spend unlimited amounts of money, but cannot coordinate their activities with those of the candidates.