Since invasion is a national sec. threat, Trump should just declare a national emergency and send the US military in and bypass Congress altogether.
Imagine having a war and having congress sue everytime the commander in chief made a new decision on where to send troops or attack.
This is ridiculous.
Congress is nearly useless. Just send the military in.
The US did this once before in the 1950’s in Operation Wetback (yes it was called that), when Mexican job robbers overran the US. The US was saved from that invasion, they were all rounded up and deported, and the US boomed for most of the 1950’s.
Squabbling isn’t going to work.