Rick Santorum’s campaign is telling reporters that the former Pennsylvania senator is growing increasingly uncomfortable with Gov. Rick Perry’s vaccination policies. In a memo tonight, a spokesman notes that ”Senator Santorum and influential conservatives from across the country share a growing unease that the more they learn about Governor Perry, the more concerned they become.” This is not a Bachmann-level attack on the Texas governor, but it’s another example of how Perry’s competitors are hammering the issue.