Seth Mnookin, a journalist who's chronicled the anti-vaccination movement, observed a few years ago that you only had to go visit a Whole Foods to find anti-vaxxers.
Now, it doesn't seem that anyone's actually done the science on that one, but Mnookin's point here is obvious — the anti-vaccination movement is fueled by an over-privileged group of rich people grouped together who swear they won't put any chemicals in their kids (food or vaccines or whatever else), either because it's trendy to be all-natural or they don't understand or accept the science of vaccinations. Their science denying has been propelled further by celebrities, like Jenny McCarthy, Robert F. Kennedy, Jr. and actress Mayim Bialik, who is also a neuroscientist and even plays one on TV.
My guess is that the anti-vaccination crowd leans way left. Among other things, they tend to cluster in far-left areas:
Researchers analyzing records for about 55,000 children born in 13 northern California counties between 2010 and 2012 found five geographic clusters of 3-year-olds with significantly higher rates of vaccine refusal. These included East Bay (10.2 percent refusal rate); Marin and southwest Sonoma counties (6.6 percent refusal); northeastern San Francisco (7.4 percent); northeastern Sacramento County and Roseville (5.5 percent); and south of Sacramento (13.5 percent). By comparison, the vaccine refusal rate outside these clusters is 2.6 percent, according to the study published in the journal Pediatrics. ...
The communities where anti-vaxxers cluster are also among the most liberal. Marin County, San Francsico County and Alameda County all voted overwhelmingly for Obama in 2008. In Marin, 78 percent of the vote went to Obama. In San Francisco, it was 84 percent. And in Alameda, it was 79 percent. That's all higher than what Obama got in his own home county of Cook County, Illinois.
So the next time one of your liberal friends starts in on science denial, point them to this one. Unlike creationism or (at least in the short run) climate change, denying the science on vaccines can be leathal.