When President Donald Trump put 2,000 National Guard troops under his control on Saturday night and ordered them into Los Angeles, it was billed as an urgent response to quell protests. But it was also a move long in the making.

Judicial precedent backs up the federal government's authority for immigration enforcement as challenges to "sanctuary" policies loom in federal courts.

But why did Trump order the raids in the first place? This is not just a matter of routine immigration enforcement, but a significant escalation of his deportation tactics. For Tr