You might be able to get away with “white nationalist” if you don’t follow it with “white supremicist” but when you string them together it looks, and is, real bad.
He has clarified what he meant. If the quote is accurate, it’s a bad gaffe for sure. But I’m not particularly interested in pandering to the outrage of a Group like the Congressional Black Caucus, at least half of whose membership sucks up to the likes of Farrakhan, who is a stone cold racist.