It's not the vaccine they are worried about, it's the asshat Perry mandating they do it that is making people mad.
He has overstepped and people are tired of it.
Not completely true. Some people are concerned about the "asshat." Many others are concerned about the unproven physical and social effects of the vaccine. Some just seem to hate the medical profession and pharmaceutical companies generally. Some think the government is colluding with pharmaceutical companies to conduct secret, widespread tests, like in The X-Files. All types have shown up on these threads.