We also have to contend with complacency.
How many marginal voters who believe a Republican victory is a given and who then don't vote?
Hatred for Trump could rally the troops.
And IF any of them do get in, they have a plan ready to go.
Yep. Alabama is a perfect example. A lot of Trump voters loathed Roy Moore and stayed home only because they were sure he'd win without them. How many watched the results come in and went, "Damn! I wasn't expecting THAT to happen!"