Right now, the two most likely candidates for the GE are Hillary and Trump. Let's look forward.

it's hard to say.

She gave the 'I love my job' speech.

many people will be surprised to learn that many of his craziest proposals are not in fact doable. Specifically, he will not be rounding up and deporting more than 10 million people. In fact, if they all threatened to self-deport, Trump's initial reaction would be to look for authority to arrest and prevent their departure. He would deem them to be essential to his hospitality industry.

I can only think of two things that he will succeed in doing: 1) He will appoint a lot of screwballs to be federal judges, young ideologues who will devote all of their energies to an effort to reconstruct the America of the 1950's. 2) He will probably have the votes to repeal the Affordable Care Act, but there will not be enough votes or political will to replace it with anything.

Who might the Democrats nominate in 2020 after four years of Trump? That's absolutely impossible to know. If Clinton loses in 2016, then there will be a lot of people who will believe that it was because she abandoned the independents who decide most presidential elections. In all likelihood, there will be many people who will look for a candidate even closer to the center of the political spectrum. If you look at the elections between 1976 (when Carter was elected) and 1992 (when Clinton was elected), you will see three elections (1980, 1984, 1988) in which the Democrats got beaten and if you look at the candidates who were nominated - Carter, Mondale, Dukakis, Clinton - you will find that the party kept moving closer to the center to find success. Eventually, Clinton won in 1992 with a very centrist agenda and with less than a majority of voters. Notice that those electoral losses did not lead to the nomination of more progressive candidates. So, if Clinton loses in 2016, I think it is highly unlikely that the Democrats will nominate anyone like Elizabeth Warren or Sherrod Brown in 2020. Parties usually become more willing to experiment with candidates further from the center as a result of political success, not as a result of political failure.

As for Elizabeth Warren, 2020 is four years off. She may be ready for a new challenge by then.