The US president described the plan by Musk, who was until recently his adviser and most prominent financial backer, to create a new political party as "ridiculous."

American history is littered with third-party bids that flared brightly only to fizzle out, he explained. George Wallace carried five Southern states in 1968 and Ross Perot grabbed nearly 19% of the popular vote in 1992 — yet neither cracked the two-party hold on the presidency.