So the renewed party polarization of the last half century began with race—the one constant and central conflict in American history—but polarization soon came to be about much more than race.55 By the years of Obama and Trump, bipartisanship in Congress had become virtually nonexistent; on six major votes of this period, the administration received support from 95 percent of their own party, but only 3 percent of the opposition.56 Statistically speaking, party polarization was rapidly approaching mathematical perfection.
