No way that is legal, to house US citizens convicted in US courts. That is a fight that will be coming. Edit: 14th Amendment. US citizens can not be forcibly deported unless they renounce their citizenship.
I don't think it's likely to come to pass (but maybe not impossible), but I think it's ridiculous that Rubio would announce this offer as if it wasn't a slap in the face. And equally ridiculous that a bunch of MAGA are probably (idk, haven't been listening) cheering the concept as if they weren't throwing their own rights into the toilet by doing so.
