Getting busted for having an ounce or less of marijuana in California is no longer that big a deal, or even a crime, under a new law signed by Gov. Arnold Schwarzenegger. Instead of facing a misdemeanor charge, people caught will a small amount of pot — an ounce is enough for about 30 joints — will now get, at most, a $100 fine. With everything else on his plate — a big budget deal, a landmark health insurance exchange — what might have motivated Schwarzenegger to decriminalize pot now? (Watch an AP report about the new law)

1. The old laws were too costly

Schwarzenegger's stated rationale for signing the bill is saving money, says Olivia Anderson in ChattahBox, and certainly "not to make it easier to get away with having pot." In fact, he underscores that he is still opposed to legalizing the drug. But "because possession of less than an ounce of marijuana is already an infraction in everything but name," Schwarzenegger says, it makes no sense to saddle the financially strapped state with the high costs of "prosecuting a crime that carries the same punishment as a traffic ticket."

2. Schwarzenegger is trying to kill Proposition 19

Essentially, "Arnold is making it harder for you to vote for Prop. 19, the November ballot initiative that would fully legalize" recreational marijuana," says Dennis Romero in L.A. Weekly. "Why legalize it when it practically is anyway?" It's a smart move by Schwarzenegger, says Josh Richman in The Monterey County Herald. Prop. 19 is up in the polls, and this law undercuts the cost-saving argument that drew many prosecutors and judges to support the law.

3. He has always had a soft spot for the green stuff

Schwarzenegger is putting the focus on law enforcement savings, says Joe Eskenazi in SF Weekly. But it's hard not to recall that scene in the 1977 documentary Pumping Iron when the former bodybuilder was "famously caught smoking a joint while eating an enormous piece of cake." You can take the boy out of Hollywood...

4. It's consistent with his cruel double standards on drug use

"The loosening in legal punishments for pot got plenty of press," says Brian Doherty at Reason, but Schwarzenegger also vetoed several measures that would have saved the lives of users of needle drugs and people who overdose. Apparently, while cannabis users are being welcomed into polite society — which shows "some good sense" — the governor believes "that anyone using needle drugs deserves whatever they get," and that is "horribly inhumane, and bad for the state's already staggering bottom line, and just plain dumb."

5. He was striking a blow for civil rights

There were 61,000 people arrested for marijuana possession in California in 2008, says the Drug Policy Alliance, and they were disproportionately African American — "even though young blacks consume marijuana at lower levels than young whites." I guess "at least on paper," says L.A. Weekly's Romero, "we can all toke a little easier now."