"Justice Scalia had an example that dealt with this situation," Alito said. "He imagined an old theft statute that was enacted well before anybody conceived of a microwave oven. And then, afterwards, someone is charged with the crime of stealing a microwave oven. And this fellow says, 'Well, I can't be convicted under this because the microwave oven didn't exist at that time.' And he dismissed that. There's a general rule there, and you apply it to future applications."
ELI5, if you please. - This seems completely invalid. Theft, the removal of an item, non-consensually, from one person by another, is not changed by this level of technology. Stealing a microwave is no different than stealing a cast iron wood stove. And yet this is put forward as some great wisdom, so legal principle. Also we're talking about immigration, and the 14th Amendment, not theft.