If push comes to shove to you think Americans would go down to the border to stop this? I wonder about that.
It's happened before. Remember the Minutemen back during the Bush II years? Thousands of patriots dropped what they were doing and went to defend our country from invasion.
Naturally, Bush quietly sicced his federales on them, and ran most of them off, so as to keep the floodgates open.
I can see the Minutemen being reborn, and under this president, they might actually get some support. At the very least, Trump would not mobilize the federal police against them.