Gödel's naturalization interview
When Gödel went to his naturalization interview, his good friend Einstein accompanied him as a witness. On the way, Gödel told Einstein about a gap in the US constitution that would allow the country to be turned into a dictatorship. Einstein told him to not mention it during the interview.
The judge they came to was the same judge who already naturalized Einstein. The interview went well until the judge asked whether Gödel thinks that the US could face the same fate and slip into a dictatorship, as Germany and Austria did. Einstein became alarmed, but Gödel started discussing the issue. The judge noticed, changed the topic quickly, and the process came to the desired outcome.
I wonder what that was, that Gödel found, but that's lost to history.
Gödel and Leibniz