You wouldn't know it from reading most science blogs, of course. They are firmly trapped in 2004 - and missed the 1990s, when Democrats were the anti-science party, killing the SSC and America's green energy program - and think that global warming and evolution are the only two science denial things happening in the country. Since it is election season, the first wave of 'Republicans are anti-science' articles has already hit and there will be a lull now that primary season is over, but efforts to insist that vaccine denial is not primarily Democrats are out in force.
How can they claim that? By ignoring all of the evidence, like actual CDC statistics, which show that while states like California, Washington and New York - liberal enclaves - have shockingly low vaccination rates - solidly religious Republican states like Alabama and Mississippi have vaccination rates over 99 percent.
Compare that to super-educated coastal California, where some schools have ~25 percent vaccination. That is not an exemption rate, that is vaccination.
How obvious is the partisan nature of the anti-vaccination movement to everyone outside science media? It is so obvious even The Daily Show is ridiculing them.
You knew this before it was cool, of course, thanks to a little book called Science Left Behind. It's nice that other have started to catch on.
H/T Rich Girard, who apparently watches The Daily Show.