How conservatism conquered America — and corrupted itself

The January 6 committee has been investigating, among other things, how it is that such a grievous attack on the Capitol could have happened in the first place. A key answer to that question will not be found not in White House call records or intercepted Proud Boys texts, but in a document released publicly last week: the Supreme Court’s ruling overturning Roe v. Wade.

That Trump would incite violence in pursuit of power was not only predictable but predicted — including by his Republican opponents in the 2016 primary. Yet Republicans elevated him...