He's not going to ignore it for now. But what happens if we get another Orlando or San Bernadino terrorist attack? He would get the full backing of Congress and a majority of American people to halt Muslim immigrants and even deport recent ones. They would beg him to write the laws, and they will willingly amend the constitution if the judicial branch tries to reverse it.
You are way too trusting if you don't think people will go along with the xenophobes immediately after an attack.
No offense, but I've been studying the constitution and US history for most of my life. Amending the constitution to destroy the life appointments of Federal judges is completely outside the realm of possibility.
Our country has been attacked by terrorists before and will likely be attacked again. Have some faith in the structure of our government. Have some faith in the 5th and 14th Amendments as well.
We have come a far way from the mistakes of Dred Scott and Korematsu.