To treat someone as evil solely because their political beliefs are in opposition to your own is indefensible as a matter of civic morality.
The only exception exists where another person's beliefs and/or actions are themselves demonstrably evil; in that event one has no obligation to serve or otherwise interact with them.
In this instance, Progressive Democrats are treating Republicans generally, and Trump supporters specifically as though they were not merely misguided, but evil. Insofar as these categories contain many millions of people, the vast majority of whom are provably not evil, what the Washington Post et al. are proposing as a supposedly legitimate course of action would in time lead to civil strife and far, far worse.
One reasonably wonders whether this is in fact their goal, or else, is it to silence the voices of dissent from their smelly little orthodoxies, the result of which would also in short order lead to repression and violence?