Political scientists are pondering the observation that people with sons are more likely to identify as Republicans and that those with daughters are more likely to be Democrats. The pols offer a bunch of reasons - men work harder, earn more and want to pay lower taxes; parents with boys go a-huntin' and a-fishin' and meet conservatives; and people with daughters understand that sometimes you can't make it on your own.
I am skeptical about whether this really stands up to scrutiny and, of course, I am not without my own stake in the game. When it comes to kids and (even at my young age) grandkids, I've got sons all day. The House of Esenberg lives on!
How about this: the Dems have identified with the notion that women are an underclass; a group of people who are victimized and need help. To the extent that you buy into that view, you'll be more sympathetic to policies that are designed to help women rise above the man's world that they must live in. Abortion, Title IX, comparable worth, cultural feminism. Its all good.
The parents of sons may be less likely to see them as oppressors.