Pres Trump knows that the Americans who voted for him will not blame him one iota if he vetoes the whole mess. Shutting down America is already being done by the democrats and republicans who are globalists.
There probably isn’t anything that Pres Trump would do in the name of the American citizen and/or for America that will cause us to turn our backs on him.
At this point I wouldn’t sign anything they want...unless they give, and then give some more!