Do we have any evidence that that has ever happened, ever ever? Based on the exit polls, we didn’t see that in 2016 (Democratic turnout was about what we expected it to be). And we know that people really like to play for the winning team, even if the team is already winning.

I am pretty confident I’ve heard that the opposite is true–that hopeless feeling like the other side is certain to win, and your vote will not change anything, can get people to stay home–but I haven’t heard anything compelling suggesting that complacency can get people to sit out an election.