Democratic-led efforts to ban vaccine exemptions in Oregon and Washington state toppled one after the other last month amid fervent opposition from parents and anti-vaccine groups who say the bills would have trampled their fundamental rights to decide how to care for their own children.
Now it's California's turn to try.
On Wednesday, a controversial bill proposed by three state lawmakers to abolish all vaccine exemptions in the Golden State -- except for medical reasons -- begins an uphill journey through the Legislature. And many observers wonder if it will encounter a similar fate.
Senate Bill 277, co-authored by Sen. Richard Pan, a pediatrician, would repeal the state's personal belief exemption and require that only children who have been immunized for diseases such as measles and whooping cough be admitted to a school in California.
The legislation would also require schools to notify parents of immunizations rates at their children's schools.
The nine-member Senate Health Committee is only the first legislative panel required to vote on the bill. If it passes there, it must make its way in the coming weeks through the Senate education, judiciary and appropriations committees, then wind its way through committees in the state Assembly. Ultimately it must clear both Democratic-controlled chambers and be signed by Democratic Gov. Jerry Brown.
But on this issue, that's no guarantee the bill will pass, said Bill Whalen, a top aide to former Republican Gov. Pete Wilson and now a fellow at Stanford's Hoover Institution.
"People think this is about people who are anti-science and not trusting of the government when in fact if you look at a map of California as to where the vaccine rates are the lowest, they're not in the Central Valley or Orange County, they're in places like Marin County and Santa Monica," both Democratic strongholds.
An informal survey of Senate Health Committee members by this newspaper found that three will vote yes, one is "leaning yes," one will vote no and the other four are undecided.