Whether or not he refuses to leave doesn't really matter. Constitutionally, any powers he has will disappear at the end of his term. If he somehow manages to wield power after that, it will only be through others in government following and enabling him, and would be a coup.

He's a coward, and this should be a non-concern. After we FIRE him we’ll have a solid two months to evict him! If nothing else - I can guarantee the Residents of DC would - if needed

The US of A, unlike most ‘western’ nations, has not had people of one religion killing people of another religion. SO FAR.

[politicalwire.com]

Let's get him to lose first. He won't be successful if he tries that. He wouldn't dare.