His opponent won the popular vote. I don't see anyone among the two dozen contenders for the Dem nom, who are likely to do as well as Clinton.
Sanders is too old. Biden is the Dem's Jeb. I think it'll be either Buttigieg or Harris (or both in some order) and identity politics isn't going to stem the Trump tide.
But on the other hand, in 2020 they're not going to take the Rust Belt for granted.
His opponent won California in overwhelming numbers. Take out California and Trump won the popular vote.
I don't see anyone among the two dozen contenders for the Dem nom, who are likely to do as well as Clinton.
They don't need to do as well as Clinton. All they have to do is take move votes in Pennsylvania, Michigan, and Wisconsin than Trump does.