The Supreme Court's reapportionment decisions, beginning with Baker v. Carr in 1962, had far more than jurisprudential consequences. They sparked a massive wave of extraordinary redistricting in the mid-1960s. Both state legislative and congressional districts were redrawn more comprehensively - by far - than at any previous time in America's history. Moreover, they changed what would happen at law should a state government fail to enact a new districting...