Yesterday’s WSJ piece on “The Fertility Gap” likely points to a real and significant phenomenon: a coming political shift rightward caused by the tendency of Republicans to have more children than Democrats. Even so, I think this approach is a bit too simple. The critical assumption here is that children follow their parents’ party politics at a rate of about 80 percent. That effect will likely persist under ordinary circumstances. But we may someday be facing extraordinary circumstances. The real question is, will the impending imbalance between older retirees and younger workers provoke an economic crisis in the West? If the economy grows sufficiently, or the retirement age is extended far enough, a crisis may be averted. If economic growth is insufficient, or if politics prevents an adequate response (as it already has in the case of Social Security reform) there may be severe economic consequences.

In the radically new demographic environment we will face in the next ten to fifteen years, social and economic changes could disrupt the usual patterns of political continuity between parents and children. In the throes of an economic crisis, radical things happen (for example, America’s sea-change shift to the Democrats during the Great Depression). A demographically induced economic crisis, or even just a long period of chronic low-level economic strain, has the potential to move politics either to the left or the right (or both). I gamed out some of the possibilities in “Demographics and the Culture War.” (And this leaves out other large-scale factors, like immigration pushing the country leftwards, or major terrorist attacks moving it to the right.)

So while the scenario sketched out by Arthur C. Brooks in “The Fertility Gap” may serve as a kind of baseline from which we’ll work, a demographically induced economic crisis could change things still more radically, in either political direction. Despite this uncertainty, the assumption that culture and politics moves ever more steadily to the left over time seems mistaken. We may be in for a gradual leftward drift, but demographic shifts have now created several plausible scenarios in which politics may actually shift rightward. So the still-widespread assumption that our culture will inevitably grow more liberal is mistaken.