The moral argument against banning of refugees from Muslims countries isn't that they are under dictatorships and therefore need saving by the great USA. Such an argument makes no sense and feeds into the "America is greatest country and leader of the free world" bizarre national mythology. After all, the USA has invaded some of the countries it now wants to ban refugees and visitors from. The moral argument against any ban should be the logical and political stance against propaganda, self-serving and misleading rhetoric.
What did the US do when Israel built a wall?! How many fingers and toes did it lift in self righteous anger?
The by product of these bans has already affected returning citizens and protected asylum seekers. Trump says he wants to only let those folks in who really love America. What does that mean?
What is citizenship in the modern world anyway? Isn't it just another privilege card in your wallet? What are citizens and what are nation states? How were these clubs formed anyway? Why are citizens of some clubs more privileged and more easily able to travel than others? Why do citizens, ordinary folks, have to bear the consequences of political elites, club rivalries and tension? And what of history? Did the Europeans get visas before they invaded and conquered swathes of the Americas, Africa and Asia? In my personal experience of applying for visas (already a humiliating and dehumanising idiotic experience), one sees how unbalanced the world regime is.
Doesn't America grant citizenship on birth? So, is that random soul born on American soil peaceful and modern and, the one who wants to immigrate to the American club a spoiler of this great utopia? One can also apply for citizenship after living in a country at length, having proved one has assimilated, integrated and become a productive member of society. One can apply for citizenship as a political or economic refugee. And, one can - poof - be a citizen just by being born there. By what measure will you judge a good citizen? A good citizen of a democracy? Voter turnout in democracies is low and more over, there so many few actively involved, educated and conscientious citizens who working together to bring about a higher level of political consciousness and societal justice.
It's unfortunate that Trump is starting out his Presidency by blame games and, banning visitors from so many Muslim countries (some of them which are wastelands of wreckage and propped up regimes thanks to American ideological wars). How will this make America great again?