[mordant]

President Trump is merely exercising his clearly-delineated powers as defined in Section 212(f) of the Immigration and Nationality Act.

You really should bone up on the law if you're going to start trying to make arguments about what's legal and what isn't, in a given context.

[ubernostrum]

Yes, you really should bone up on the law:

https://news.ycombinator.com/item?id=13529036