Because: What you permit, you promote.
If you're a Democratic voter busily denouncing Trump's power grab in national terms, stop and take a deep breath. Look around you. Your local Democratic Party leadership is revealing itself to be just as undemocratic and morally bankrupt as those GOP leaders you love to hate, and the mayor is busily amassing as much personal power (and a great deal of campaign finance) as he can manage while you're busy looking the other way.
There are many courses of action that might help restore balance to the world, but must raging hypocrisy be one of them? If you're against it when Trump's doing it, mustn't you also oppose it when the perpetrator is Jeff Gahan or Adam Dickey?
Or it somehow different then?