But here is one. Indiana just passed statewide education vouchers. How a policy like that isn't becoming law in Texas, Alabama, etc. when they have had GOP legislatures for a while, I have no idea.
I think voucher systems are more popular in areas with a high percentage of white Catholics. Public schools have historically been the domain of Protestants and Catholic families paid for parochial schools. In the South, the division has been on race, not religion. I'm not sure even Alabama's or Mississippi's legislatures from the 1960s were brazen enough to issue vouchers for students to go to white only academies. Since the percentage of white Catholics (I say white, because TX does have a high number of Hispanic Catholics) has been historically relatively low in those regions, the impetus for voucher programs probably corresponds.
But again this is about voters here. And New Hampshire still has a lot of Boston suburb liberals.
I've never been to New Hampshire, but have been to Boston a number of times. It has always been my impression that SE New Hampshire (the Boston suburbs) has been, in recent times, the most conservative part of the state. Rockingham County went Obama by the smallest margin of any NH county, and went R in '00 and '04.