Apparently, California's prison guard union (CCPOA) has a history of lobbying against measures that would reduce the prisoner population and/or reduce state spending on prisons:
1994: With the help of CCPOA’s $101,000 support, Californians passed Proposition 184, the nation’s toughest three-strikes law mandating 25-years-to-life sentences for most felony offenders with two previous serious convictions.
2000: The CCPOA contributes at least $75,000 to the opponents of Proposition 36, the 2000 initiative that replaced incarceration with substance abuse treatment for certain nonviolent offenders.
2004: The CCPOA spends over $1 million to defeat Prop 66, the initiative that would have limited the crimes that triggered a life sentence under the Three Strikes law.
2005: The CCPOA defeats Governor Schwarzenegger’s plan to “reduce the prison population by as much as 20,000, mainly through a program that diverted parole violators into rehabilitation efforts: drug programs, halfway houses and home detention.”
2008: The CCPOA contributes $2 million to Jerry Brown’s gubernatorial campaign. The CCPOA contributes $1 million against Prop 5, a measure to reduce prison overcrowding by providing treatment rather than prison sentences for nonviolent drug users.