If he had nothing to hide, no heinous acts to run from, etc. then why did he lie when he entered the U.S.?
There were many former Nazi officials, members of the SS, etc. who emigrated to the U.S. after WW2. They were investigated a great deal more than other Germans (names compared to 'watch lists', more interviews conducted with associates and people from the region in Germany that the person was emigrating from, etc.) but in the end no small # of them were allowed to emigrate.
This guy lied and he lied for a reason. How long it has been does not matter. He lied to gain entry to the U.S., and now he has to leave. Sure, it's been 59 years. It's also been 59 years for a bunch of innocent people who spent those 59 years missing murdered Mothers, Fathers, Children, and other relations.
I know that plenty of people who had some punishment coming slipped through various political cracks (Emperor Hirohito, numerous Japanese military and government types, other Germans, etc.). That doesn't mean you let others 'off the hook' as well.
As for the 'all Nazis should be shot' - revise it to 'anyone found guilty of crimes against humanity should be punished accordingly'. The mayor of a town was a Nazi by default once Hitler took over. Nazi is a title. Murder is a voluntary act.
Mike/wulfie