Because only adults vote, you have to factor in the rate of religious retention for these communities. If 60% of the offspring in a religious community are are

Because only adults vote, you have to factor in the rate of religious retention for these communities. If 60% of the offspring in a religious community are areligious, the opposite effect will occur. And this belief/concern presupposes that in democratic societies the political power is held by voters, which I feel is highly reductive even for the most effective democracies