I'm not sure if it's reflective of the deteriorating state of Trump's mind that the story that his administration contemplated shipping off migrants at the border (people seeking legal asylum, fleeing violence and civil war in Central American countries) to sanctuary cities has gone through denials, admissions and then thrown out again as a possibility, then again as a definitive threat. Apparently, Trump has no problem instituting policy as some sort of petty, vindictive move to punish communities for not buying into his fear mongering. But he also doesn't have a problem making up crap just to play to his base either.
Oakland mayor Libby Schaaf had the best possible answer to this: Bring it.
Schaaf appeared on CNN and NPR’s Weekend Edition to condemn the President’s proposal, saying she was “proud to be the mayor of a sanctuary city.”
“This is an outrageous abuse of power and public resources,” she said Friday on CNN. “The idea that the administration thought in any way that it would be acceptable to use families and children, human beings, as political retribution against their enemies should infuriate every American regardless of political affiliation.”