The best approach is to go into election day mentally prepared for a wide band of outcomes—in both directions. The least surprising thing in the world would be if polls overstated Dem support, leading to a disappointing night for Dems. We’ve all been there. But polls have been pretty reliable in midterms and right now all the other signals—prices, consumer confidence, party ID—are pointing in the same direction as the polls. I won’t be surprised to be disappointed but I also won’t be surprised to see a wave bigger than any we’ve seen in a long time.