From the first years of a century already one-fifth completed, we’ve been told that a new, ascendant America — more nonwhite, more culturally liberal, more feminist — was going to dominate our politics for years to come.

Those predictions have, partially, come true. Barack Obama was elected and reelected president in 2008 and 2012, and Democrats won majorities in House contests in 2006, 2008, and 2018.