But progressive independent Bernie Sanders had a wry view of a third Trump bid.
"As an American, the idea of another Trump campaign and all of his lies and divisiveness and his efforts to undermine American democracy is an absolute horror show," he said.
"On the other hand, I got to say that as a politician who wants to see that no Republican is elected to the White House in 2024, from that perspective, his candidacy is probably a good thing."