I don't remember Jimmy Carter certifying Hitler's election, but I could be wrong.
Hitler became Kanzler by appointment from von Hindenburg on 30 January 1933, in what was supposed to be a compromise coalition government with Franz von Papen, a former failed PM, serving as vice-chancellor. That arrangement lasted about 18 months, by which time von Hindenburg had died and Roehm's SA had eliminated the majority of Hitler's opponents' leadership, then was himself killed on Hitler's orders.
That the myth of Hitler's ''election'' is so persistent is absolutely astonishing. One would think that a smart chap like Rummy had read his history at some point. Guess not.