In crowded primaries, Republicans will be rooting from the sidelines for the liberal base to pull all of the candidates leftward — forcing them to declare allegiance to single-payer health care, impeaching Trump, free college tuition. Those are October attack ads in waiting in many of the scattered pockets where Democrats need to win.

Which is why national numbers matter so little. For an electoral wave to rise high enough to wash a majority-making two dozen House seats into the Democratic column, the party will have to take territory that Hillary Clinton could not.

There again, Virginia offers reason for caution as well as hope for Democrats. They romped the Old Dominion in November, picking up 15 seats in the House of Delegates. But that victory fell one seat short of what Democrats needed to break the GOP majority. And 14 of those were in legislative districts that Clinton also won, suggesting that the party had done little to expand its reach since 2016.