One of the many big surprises in this month's surprising election was the Democrats' failure to overturn Republican majorities in state legislatures. Various Democratic committees budgeted $88 million to flip majorities in big states such as Texas, Florida and North Carolina. Total gains: zero. That's a bad return on lavish investments in money and psychic energy. Liberals have been bemoaning partisan redistricting as a betrayal of democracy, as politicians removing choice from the people. Such rhetoric is overheated and ahistorical. Those who have followed redistricting since the Supreme Court's equal population decisions in 1964, as I have, know that redistricting...