The clever marketing of the Nazi party still seems to work like a charm some 90 years later.
The name "National Socialist German Workers' Party" was deliberately chosen to simultaneously appeal to two very different constituencies (remember that the Nazis legally accessed power through winning the 1933 elections):
– "National German Party"
– "Socialist Workers' Party"
People simply dropped/ignored the words they didn't identify with and voted for them. The rest is history.
Oh, and unlike Elon insinuates, one of the very first acts upon getting into power was to imprison, torture, and kill actual socialists.
Hitler was also left, just a different type of left. Hardcore socialist.