The explanation touches on this principle.
Analogous to how fascists (and Trumpism is a form of fascism) believe that whatever the fascist leader says is by definition always right, fascists believe that only political outcomes that create fascism can ever be legitimate. Therefore any election that undermines Trump’s power must by definition be illegitimate.
A blue wave election will be said to be the result of millions of illegal aliens voting, the result of foreign collusion, the result of Deep State collusion, or any number of other pretexts. Even if the winners are allowed to take office (and it’s an open question if all of them will be), the resulting Congress, and anything it does, will be “illegitimate” in Trumpist eyes.
The same will apply to any presidential election in 2020 that fails to return Trump to office, or to place Trump’s annoited successor into office. It will be “illegitimate.” Odds are high that Trump will declare a state of emergency and refuse to leave office if he runs and loses in 2020. And that’s if he doesn’t declare one and try to override a Democrat-controlled House or Senate first.
Ultimately, the only solution is likely to be a willingness to fight Trumpism via various means of direct action. For the time, I do plan to support electoral means of reining Trump in, but I don’t expect widespread success.
I’m mainly doing it for sake of argument so that I can confront liberals later with an example of the demonstrated impotence of their chosen method: I chose to suspend my doubts and help you try it your way, it didn’t work, now can we discuss other means?
I only hope that this works. A big part of me worries that liberals are in general so terrified of taking any personal risks that they will by and large opt to choose submission to fascism over struggling for liberty.