Henry Ford was a very ambitious man and the rise of Fascism in Italy and other such Nations would likely embolden him. Remember that he had his own National Paper and he could successfully convert that into a propaganda machine for his movement. He might see how hard it'll be to win in '28 and will instead run in '32, as he'd 69 and the breaking off Point for Presidential Candidates seems to be mid-late seventies for a 1st term.
Eh, given that he only had an 8th-grade education & was something of a control freak, I suspect that he may prove to be a bit of an embarrassment to the Democratic Party were he to have actually sought the Presidency.