After Abigail Spanberger won the Virginia governor’s race going away in November, the consensus among the political chattering class was that it’s a foregone conclusion the Republicans will lose in next year’s midterms. The experts said this was a referendum on President Donald Trump, and an early sign that his America First movement is cracking. The same experts pointed to “key Democrat wins” in the New Jersey governor’s race and the New York City mayoral election as further indicators of a coming blue wave. To be so smug in their predictions, the experts had to ignore the fact that the...