In 2014, my firm, GreenDog Campaigns ran an Assembly race in California's 10th Assembly District for Community College Trustee Diana Conti. She was running to oust a "moderate" Democrat, Marc Levine, who had been elected in 2012. In this overwhelmingly Democratic District, she could easily have come in second to take on the incumbent in the fall, (Califonria has a top two primary, which has seen brutal Dem on Dem fights since 2010), if it were not for some last minute "independent" mailers that boosted the Republican's chances int he primary.
Consequently our candidate was edged out of second place by the Republican, thereby assuring a win for the moderate Dem. We saw a similar thing happen in the special election in District 7 this year. The election in May is now between a moderate Democrat and a more progressive Democrat. If Republicans come out to vote for the moderate, we could see another progressive District go the way of the dodo bird.
This Sacramento Bee article describes the phenomenon: http://www.sacbee.com/...