Hillary Clinton will win the national popular vote.
This is a lot less relevant than it seems. Legally, of course, it's entirely irrelevant: we elect our President through the electoral college system, not the popular vote. And even as a talking point, its bark is worth more than its bite. Just because Hillary Clinton won the popular vote under the system we have (where the popular vote isn't the prize) doesn't mean she would have won had a popular vote plurality been the deciding factor. Both candidates' strategy would have been very different had the popular vote been the deciding factor; perhaps if Trump had an incentive to focus on ginning up more votes in, say, Los Angeles, the numbers would work out differently. It's not implausible that Clinton would have won the popular vote anyway, but it's a hypothesis supported by moderate -- not overwhelming -- evidence.
Nonetheless, the fact that we've now had two elections in 16 years where the popular vote winner was the electoral college loser has put our status quo system under unprecedented scrutiny. My inclination is to support reform: it's hard to justify the electoral college (particularly since it is about to fail at one of its original justifications -- ensuring that a wave of populist demagoguery doesn't put a manifestly unqualified hack in the oval office).
Perhaps the only plausible contemporary justification for the electoral college I've seen is that it forces candidates to appeal to a wide range of Americans, instead of just concentrating on big cities. Who would spend time in rural states like Iowa or New Hampshire were it not for the electoral college incentive? The claim is that, if we only decided things by the popular vote, our presidential election campaigns would be fought out only in our biggest cities, leaving many Americans on the outside looking in.
I don't find this objection compelling for two reasons. First, the electoral college also very obviously causes large swaths of America to be overlooked. "Safe states" like California or Texas (or Delaware or Wyoming) are entirely ignored. And if certain regions have to be ignored in a democratic system, in a democracy it seems like "having fewer people" is a pretty decent metric for allocating our attention.
But second, I'm actually unconvinced that we'd see widespread neglect of rural America in a popular vote model. The way actual presidential campaigns operate in swing states is illustrative. In Wisconsin, for example, it's not like Democrats and Republicans spend all their time fighting for votes in Milwaukee and Madison, and ignore the rest of the state entirely. Rather, there is plenty of attention paid to the outlying regions -- particularly by Republicans, who try to drum up support from many smaller counties to counteract huge Democratic margins in the cities. This seems to be pretty standard across most contested states. So why wouldn't we see the same dynamic play out nationwide: Republicans rallying many small-population regions to try to overcome large Democratic margins in cities?
And this brings me to my final observation. I support a national popular vote model because it seems more democratic than our status quo. But I think people are being mislead in thinking that it necessarily benefits the Democratic Party. Many large urban centers are in blue states that are not currently contested. Many rural areas, by contrast, are in purple states which are absolutely contested. In other words, our political system right now has Democrats and Republicans nip-and-tuck in a situation where Democrats do try to appeal to rural and exurban voters, and Republicans basically don't try to appeal to urban voters. It seems like the GOP has a lot more room to grow if, as it'd have an incentive to do in a popular vote system, it starts making a serious play for city votes (it's also true that in doing so it may have an incentive to moderate itself by appealing to a more diverse constituency that it currently ignores).
Again, my small-d democratic preferences aren't based on what helps the large-D Democratic Party. But this is a note of caution about thinking that a popular vote model will necessarily be a boon for progressives. It may well help the GOP more (though it also might help the GOP break out of its increasingly radical shell).