Updated at 8:45 a.m.
He also expressed worry about the "tendency to go to extremes." After legalization, he said, "if there's advertising and legitimacy, how many people can get stoned and still have a great state or a great nation? The world's pretty dangerous, very competitive. I think we need to stay alert, if not 24 hours a day, more than some of the potheads might be able to put together."
A December 2013 Field Poll showed that a majority of Californians — 55 percent — approves legalizing marijuana use for the first time since pollsters began tracking opinions on this issue in 1969. Several groups have been collecting signatures for three legalization ballot measures this year, although the competing efforts have made fundraising for a 2014 vote difficult.
California became the first state to legalize medical marijuana use in 1996, when 56 percent of voters approved Proposition 215.
Correction: An earlier version of this article said Proposition 216 was passed in 1996. Proposition 215 legalized medical marijuana in California in 1996.