T here’s a certain freedom in low expectations. Going in to Tuesday’s midterm elections, forecasts were so grim for the Republicans that poll watchers started trading a kind of knowing joke: that the results would either mean the end of the Trump era, or the end of the polling profession.

Amid those sorts of predictions, any Republican victories would have seemed like a minor miracle. The expectation was that Democrats would have a blowout; Republicans, counting on the final tally to be a bit more mixed, would therefore almost certainly have the freedom to claim that they’d done better than anyone had thought they would.

It will be difficult to credit those spins today.…