1.  There is no constitution right to immigrate to America.
2.  Trump's XO is as legal as Obama's 6 month ban on immigration was.
3.  The XO is not a "religious test".  It's fully constitutional to impose a moratorium on importing members of a religious cult whose priests (Imams) and teachings (Q'uran) instruct them to murder anyone not in their cult.
4.  Preventing immigration of Muslim terrorists protects America much better than Obama's seeding of Muslim terrorists throughout America's rural areas, where they can grow into a formidable force to be called to rise up and strike their generous but naive American hosts.
5.  Enshrined in the constitution is the idea that Americans have a right to live free from fear of murder by Muslims.
6.  Not enshrined in the constitution is the right of any foreigners to come to America.
6.  There are no "refugees", only migrants bent on colonizing and eventually overrunning America, see The Muslim Doctrine Of Immigration, the Hijra (hish'-ruh).