Citing parental freedom, Arizona lawmakers move ahead with anti-vaccine bills
arstechnica.com
arstechnica.com
There's evidence that trolls have significant involvement in anti-vaxxer forums, and the incidence of bad actors and manifest failure of the best available information to naturally displace falsehoods suggest that our model of public discourse is severely lacking in explanatory power.
Measles doesn't spontaneously appear within a community; it's brought in from the outside.
There might well be a different explanation for outbreaks in different places; I am certainly not asserting this as a universal causal factor.