Trump won't need to rally his base in 2020. They'll be there no matter what.
But his base appears to be only about 30% of the electorate. That's not
enough to win reelection and what he'll need to do is hang on to the swing
voters who helped him win in 2016. He appears to already be losing many
of them. In interviews they have made it clear. They voted for him on the
basis they thought he was committed to improving the lives of working
class/middle class people. But he's demonstrated that he is not.
I look at the past dozen elections and voter participation ranged
from 50% to 60% of the electorate, which means that the much
maligned Electoral College actually randomizes the election.
In a world without the Electoral College, the Republicans
who have an advantage from 0% to 10% could win forever.
Anyway, voter education definitely needs fixing, a few hours reviewing
his history would've removed the silly idea he cares about working people.