I see Trump is threatening a government shutdown if he doesn't get border wall money in the budget this time. Ironically, any shutdown would make ICE and Homeland Security employees work without pay! So it's kind of like most Trump threats, in that it has an instant backfire built right in.
But it also brings up another interesting point: Trump can't shut down the government. He can veto a budget bill, but the last one passed with nearly veto-proof majorities in both Houses of Congress. If he did veto a bill, Congress could probably whip a few stragglers into overriding.
Does this portend the next two years? Congress just passing everything with veto-proof majorities and ignoring Trump's tantrums?