I think Larry Sabato’s 2016 presidential analysis is pretty solid. But it’s a little thin on detail. For example, he fails to mention that Govs. Scott Walker of Wisconsin, Chris Christie of New Jersey, John Kasich of Ohio first have to win reelection before they can make a strong case to be the Republican nominee. At least in the case of Walker and Kasich, reelection is far from a sure thing. Sabato also spends too little time exploring the earthquake that would result if Rick Santorum or Rand Paul or Ted Cruz were actually to win the nomination. In any of those cases, the Republican Party would be fractured beyond recognition.
On the Democratic side, we’re stuck having a bifurcated debate with Hillary in the race and without Hillary in the race. He’s probably right that Elizabeth Warren is the only possible candidate with the potential to beat back a Clinton nomination. I just doubt that she’d make the effort. I also think potential is not the same thing as likely. A Warren vs. Clinton fight would badly split the party, and Clinton would probably prevail in a weakened state. However, if Clinton doesn’t enter the race, it will be truly wide open and almost impossible to predict.