They may be, but if there are no elections, there is no United States. Constitutionally, its government is predicated on having elected representatives.
I could see Trump trying this, but I also can see dozens of other people or groups, some richer, more powerful, more competent, and more ruthless than Trump, just waiting in the wings for the guardrails to come off to make a play to rule the territory of the former United States. If he tries and succeeds at this it's open-season. It's not a Trump dictatorship, it's a civil war, akin to the Chinese Civil War after the emperor fell or the Syrian civil war after the Arab Spring.