Don't blame me, I've done my part!

From the WSJ:

Simply put, liberals have a big baby problem: They're not having enough of them, they haven't for a long time, and their pool of potential new voters is suffering as a result. According to the 2004 General Social Survey, if you picked 100 unrelated politically liberal adults at random, you would find that they had, between them, 147 children. If you picked 100 conservatives, you would find 208 kids. That's a "fertility gap" of 41%. Given that about 80% of people with an identifiable party preference grow up to vote the same way as their parents, this gap translates into lots more little Republicans than little Democrats to vote in future elections. Over the past 30 years this gap has not been below 20%--explaining, to a large extent, the current ineffectiveness of liberal youth voter campaigns today.

Alarmingly for the Democrats, the gap is widening at a bit more than half a percentage point per year, meaning that today's problem is nothing compared to what the future will most likely hold.