Hillary Clinton holds a 4-point lead over Donald Trump in the waning days of a volatile campaign that has left many voters dissatisfied with both candidates and the political system, a new Wall Street Journal/NBC News poll found.

Voters, facing a lesser-of-two-evils choice, have ended up more worried about the Republican nominee’s temperament than about Mrs. Clinton’s email controversy, the poll found. But the race is tightening as Republicans rally behind their nominee at the 11th hour.

The...