Talk me off this ledge, because it's been nagging at me for days

[TwilightZone]

21. They're not cannibalizing anything.

The total number of votes is the same, at least, and almost certainly higher.

Relying solely on election day voting was always dumb. Lots of things can happen that keep someone from being able to vote that day. By voting early, those potential issues are avoided.

Assuming that all of the R early voters would have voted on election day and would have been able to, it's the same number of votes in total. For every voter who voted early who, for whatever reason, would have been unable to vote on election day, the total is one higher.

Your assertion that we just have to outvote them is correct, of course. But early voting is going to help them overall, just like it's helped as long as it's been around.