And Republicans have to some extent been victims of their own success. Gerrymandering is only a minor factor in the polarization of the U.S. political parties — a major factor is the Democrats’ cultural turn to the loopy left — but the creation of safe Republican districts has been a non-trivial factor in the increasing willingness of hard-line conservatives to stage primary challenges to GOP incumbents deemed ideologically limp. Running against a sitting Republican incumbent in Oklahoma or Utah is a great deal more attractive when the primary is a tougher fight than the general election. But the parties are going to be increasingly polarized with or without partisan electoral maps.

If Democrats are unhappy with Republican domination of the state legislatures and governorships — and they should be unhappy — then they have a much more direct option: They can go into the states and ask people for their votes in legislative races and in gubernatorial elections. If they find that route difficult, then maybe the Democrats should be rethinking what they’re trying to sell people in Wisconsin . . . and in Texas, Arizona, Utah, Idaho, Wyoming, the Dakotas, Kansas, Nebraska, Oklahoma, Michigan, Iowa, Missouri, Arkansas, Mississippi, Alabama, Georgia, South Carolina, Florida, Tennessee, Kentucky, Indiana, Ohio, New Hampshire, the parts of New York more than 70 miles from Grand Central Terminal . . . .