Anecdotally speaking, I can tell you that I’ve probably become less libertarian and more communitarian since having children a few years ago. If one concedes that at least some of our political preferences are based on self-interest, then this is perfectly natural.

For example, as an adult, legalizing drugs, prostitution, etc., probably wouldn’t have terribly negative consequences on my life. If anything, it might even increase my liberty…

But if one is also concerned about the larger culture — not just academically interested in the “future,” but intimately worried about the next hundred years — well, that might lead to dramatically different conclusions.

Putting aside overt politics, if you have kids, you may find that (if you didn’t realize it before), you suddenly have a vested interest in communities having strong schools, churches, etc. This isn’t so much a left vs. right thing as a communitarian vs. individualism thing.