There are many reasons why Maine is superior. Take the crime rate, for example. Some could argue that these crimes might have no impact on children, so let's look at the child abuse rates. These numbers portray a safer environment in Maine. Money isn't everything, but certainly a poverty-level lack of income won't help in child rearing.
Education is another important factor to consider.
I believe this is due to a much smaller population, which, in turn, produces smaller schools. I graduated with a class of thirty-six students. Individual attention was not a problem. Pregnancy rates per 1000 teenage girls in 1996 prove this. Preventing teen pregnancies will help keep the high school graduate level high and, consequently, keep the poverty level low.