I like the way you think
Actually though, evangelicals tend to expand through families. In other words they get the children. They also tend to get converts through the socioeconomically vulnerable, like addicts/alcoholics, people who are down and out. They offer community, love and support which comes attached to the religious messages. When one is really struggling long-term and in a dire negative head space, the conflation of loving support with religion may become automatic. One may assume that because these people are so loving that their religion may also be worth considering.
I say this as an ex-Catholic who grew up in the Church life. I get it, I really do. I'm not even claiming that Jesus, as a force, is unreal or irrelevant. I'm just talking about this as a political phenomenon. The evangelicals are a tour de force and not in a good way. It's a lot of traditionalism and entitlement wrapped up into one, which forms a nice righteous package.
Society becoming atomized is an interesting way of looking at it, and yes I can see the problems there. My main beef is that our polity has been gamed. Our secular system which is supposed to operate on secular evidence and gathering of information from constituents has now been gamed. Everyone is trying to push through their political message through populism rather than rational appeal: evangelicals, leftists, rightist, etc. Look at the President we have now. He played the populist game and won, no real qualifications necessary. Too many people are trying to go above it or underneath it rather than the fair and democratic way which is through it.