To many California political insiders, the idea of the state adopting a Canadian-style health plan — run by the government with care delivered by private doctors and hospitals — seems fanciful. Gov. Arnold Schwarzenegger has already vetoed the proposal once and has threatened to do so again if it lands on his desk before his term ends in January. California voters also rejected the idea when it appeared on the ballot as a citizens’ initiative in the 1990s. And with President Obama and the Democrats in Congress trying to pass a comprehensive health care plan for the nation, this seems like a strange time for California to do its own thing. Don’t tell that to Senator Mark Leno. The San Francisco Democrat, is moving ahead with his single-payer proposal, a measure he inherited after Senator Sheila Kuehl, Democrat of Santa Monica and a longtime champion of the idea, was forced from office by term limits in 2008. My column in today’s New York Times’ Bay Area Edition explores what’s ahead for the idea in California.