Bill Weld (R.)
Updated: Oct 2, 2019
Quick Bio: Bill Weld was the governor of Massachusetts and has been a United States Attorney under the Reagan Administration. He is recently best known as the candidate for Vice President for the Libertarian Party in 2016. He is the first Republican after Trump to form an exploratory committee for the 2020 election.
Pros: Bill Weld and Gary Johnson broke the record for the Libertarian Party votes in 2016. Maybe it was due to the disgust of the Republican and Democratic Party candidates or it was because they were more likely to focus on domestic issues was key. Regardless, Mitt Romney remarked that, "if Bill Weld were at the top of the ticket, it would be very easy" for him [to support the ticket]. To be fair, the Libertarian ticket was a nice side-show from the main event.
Cons: Foreign policy is an corner of Bill Weld's brain. Remember Allepo-gate? That's when he was asked what he would do about Allepo. He replied, what's a lepo? Allepo in any other context would get this kind of reply any other time, but during 2016 the humanitarian crisis in Syria was all over the news. The lack of foreign policy credentials is frightening.
Conclusion: I doubt Bill Weld has much of a chance and he knows it. He hasn't held any official office since the 20th Century. Considering he's running against Trump, should Trump win, I doubt he'd have a spot reserved in the administration. That said, he's doing this because he's anti-Trump. He knows any challenge to Trump in the Primaries is likely to weaken the President as he goes to the General Election. Bill Weld too Libertarian for the Republicans and is too Republican for the Libertarians.