Originally Posted by Matt 26z

Entering the US illegally isn't a misdemeanor when the organized motive behind it is a low key act of war with the goal of conquering new land.

Much of the border area was once owned by Mexico, but they will never attempt to redraw the borders to formally reacquire it. Instead, that land is worth more to them still being a part of the US and having Mexico loyalists living there and running things.