“any normal person sitting in the oval office would’ve done the same thing as FDR (perhaps besides sending the Jews on the St. Louis back).”
FDR had no authority to admit the St. Louis passengers. You had to have a visa issued at a US embassy or consulate in your country of birth. That was the law and had been the law since 1924. This was particularly problematic for Polish born Jews because Poland had ceased to exist in late September 1939.