With his unabashed racist remarks and determined political incorrectness, Donald Trump is riding a wave of protest against political establishment toward the White House.

Both at home and abroad, the prospect of Trump becoming president of the United States fills many with alarm.

Such is the concern that even Republican Party colleagues have tried to get rid of him. Former president George W. Bush is reportedly worried nominating Trump might mean he is "the last Republican president" and spell the end of the GOP.