If you thought Donald Trump was certain to be the 2020 Republican Nominee, it may be time to think again.
Last week, Bill Weld became the first to throw down a challenge, slamming the president as ‘too unstable to carry out the duties of the highest executive office’.
Few regard Weld himself as a serious threat but it may open the floodgates. Plenty have called for a challenger and several have flirted with the idea.
Here are my ratings: