Believing in a vaccination/autism link is not the same thing as opposing vaccination; it's the 10% that's the relevant statistic there.
Longtime forumgoers may remember me supporting the thimerosal/autism hypothesis some years back, but I NEVER said people shouldn't vaccinate their kids, only that we should find a preservative that doesn't contain mercury. The link has now been thoroughly refuted and its major proponent exposed as a liar and a fraud. I backed the wrong horse, and have no problem admitting it -- that's science; you go with the information you have and, if better information comes along, you go with that instead.
While it's troubling that 25% of the population still believes in the link even though it's been debunked, it's heartening that most of that group still vaccinates their kids anyway. And of the 10% of the population that refused at least one vaccination, well, we only know from that data that they refused at least one vaccination -- and we don't know what or why. There are occasionally valid reasons to refuse a vaccination: my girlfriend's mother stopped having her vaccinated for rubella after she got rubella from a vaccine. It's extremely rare but it happens. (Though I don't have stats in front of me and maybe it's not common enough to make a statistical dent in that 10%.) And the article even mentions the chicken pox vaccine on page 2 -- refusing the chicken pox vaccine is pretty damn different from refusing the polio vaccine.
And even if we go by the 25% statistic -- it's hardly a subset of "potential Bachmann voters". There are plenty of liberals who buy the autism/vaccination link. It's one of many reasons I no longer read the Huffington Post.