Today, we are less divided over race, but more divided over sex and reproduction. In a country that cannot agree whether fetuses are human beings, even questions like how to mourn and bury a miscarried child are inevitably freighted with ideological significance. Likewise, in a country where the majority of Down syndrome fetuses are aborted, the mere act of carrying a child with a genetic disorder to term — as both the Palins and the Santorums, whose daughter Bella has Trisomy 18, have done — feels like a political statement…

When Palin wove special needs children into her 2008 speeches, or when Santorum featured his daughter Bella in a campaign video, they were implicitly acknowledging these personal-is-political realities. Likewise Mitt Romney, who ran an ad highlighting his 42-year marriage at the height of the twice-divorced Newt Gingrich’s surge in the polls.

But by turning their personal choices to political ends, politicians lose the right to complain when those same personal lives are subject to partisan critiques. They can and should contest these critiques, but they can’t complain about them. In a culture as divided about fundamental issues as our own, the kind of weird attacks that Rick Santorum is enduring come with the vocation he has chosen.