I absolutely believe that daycares and schools (anywhere that children gather) should be allowed to turn away willfully unvaccinated children. Kids with legit medical reasons, is a different story.
In Kentucky, when I enrolled my son into school, I was asked if my son was vaccinated, and if not was it due to religious preferences. My son was vaccinated, but I knew multiple people who didn't vaccinate and claimed it was for religious reasons. The honest reason though, was they were lazy shit heads who couldn't be assed to take their kid to a clinic to get the shit done for free.
Between that and my experience with other people who genuinely believed their reasons (whether it was the not natural horse shit, or anti government stuff) I lost most any sympathy I once held for anti-vaxxers.