Once the Immigration and Naturalization Act of 1952 passed Congress they could be.
USC 8 all the way. It changed everything and was fully Constitutional. Congress acted in their authority.
Time didn’t stop the day of those debates. HUNDREDS, if not thousands of changes have been made to immigration law since then.
Nice resource page.
again, congress can pass whatever laws they want...
their laws cannot modify the meaning of the Constitution or try to supersede it.
if they pass laws that are not Constitutional then they’ll get tossed once it’s challenged at SCOTUS