I have finally figured out who Trump reminds me of. I once thought he was a new Huey Long, or another Ross Perot, and he does have elements of both. But the man he most resembles is Oswald Mosely of England.
Mosely started out as a conservative, and Trump too, at times, has expressed some semi-conservative ideas. But, like Trump, Mosely eventually tired of conservative opposition to some of his more outre ideas and became an independent member of labor, often espousing socialist ideas. Kind of like Trump telling us Hillary would make a fine president, or supporting some sort of national health care scheme. Eventually, before the second World War, Mosely founded the British Fascist Union, combining Fascist "corporativism", a sort of guild socialism, along with racist ideas. He was eventually interned by the British during the war, and afterward became a proponent of "Europe as Nation", trying to argue for a unified, Jew-Free, black-free Europe.
The pattern is not exactly perfect, but it is pretty close. Trump lacks Mosely's rhetorical abilities, and Mosely did not quite have the populist tendencies of Trump, but otherwise, from criticism of bankers, to racist rhetoric, to praising the "strength" of foreign dictators and promising to revitalize a nation, the two are definitely of a kind. Even the strange path from conservative to socialist to fascist sort of fits with Trump's all over the map policy ideas.
So, until I find a better comparison (and Mussolini may be my next one to examine in more detail), Trump is going to be Oswald Mosely in my mind.