Hitler was a "foreign puppet"? This is news to me, can you tell us who the puppet master was? Because it seems to me that person should be as widely reviled as the man himself.
Wait so the real issue you have is with foreigners, or what's the point here? If he was born in Germany it would've been ok? Don't dance around your point, just be explicit.
If you go back up the thread, you will notice that I originally (https://news.ycombinator.com/item?id=43407532) brought up the point that restricting who Americans can vote for is a bit silly, and that includes banning them from voting for foreigners. If the voters want a foreigner, they should get a foreigner. (As long as the foreigner is willing.)
I have no issues with foreigners. I think voters should be free to vote for any willing candidate, and people should also be free to move and work wherever they feel like, as long as they find a willing landlord (or house seller) and as long as they find a willing employer. I myself am a foreigner in my adopted home.
Now to your question:
In this subthread we were looking at the question of any actual examples of foreign born leaders causing trouble for their host country.
In the interest of intellectual honest, I have to admit that a US-style banning foreign born leaders might have conceivable stymied Hitler's rise to power in Germany.
Especially because by the time Hitler entered government in the Weimar Republic, the economy had already started to recover, unemployment was going down. So any roadblocks and delays might have conceivably gotten us over the limited time window where inviting the extremist to share power was even seen as a good idea to try.
Now obviously I could argue against this point; or argue that Hitler would have just put a local-born puppet to be his front man in government, etc.
But that's a more nuanced and fragile argument than the one I would have liked to make: that the US-style ban on foreign leaders is silly and never ever hindered any would-be bad guy.