The National Institute on Money in State Politics offers this report.  A synopsis: “Political spending practices in California were unaffected by the U.S. Supreme Court’s Citizens United v FEC ruling. Although the ruling permitted corporations and unions to spend unlimited amounts of money from their general treasuries to independently advocate for or against candidates, corporations and labor unions in California had not previously been banned from doing so. This report analyzes California’s reported independent spending data and reviews the quality of independent spending disclosure in California from 2005 through 2010.”