From Adam Nagourney in the Times:

SANTA ANA, Calif. — Orange County has been a national symbol of conservatism for more than 50 years: birthplace of President Richard M. Nixon and home to John Wayne, a bastion for the John Birch Society, a land of orange groves and affluence, the region of California where Republican presidential candidates could always count on a friendly audience.

But this iconic county of 3.1 million people passed something of a milestone in June. The percentage of registered Republican voters dropped to 43 percent, the lowest level in 70 years.

Thanks to the Analog Sherpa for the link.