Any action taken on the basis of the 2nd amendment will be met with overpowering and superior force from agencies and even the military with tools that the very very few Americans willing to take up arms would stand no chance standing up to. To assume the government would have ROEs like are used abroad against Americans is foolish.
But it would stop the mad rush at the border and force the the Government to keep military garrisons there which would likely slow the flood. The Dems would be stuck with the optics of having to use the military to allow the illegal aliens in.
I didn’t say it would be easy.