I think before we start pointing fingers, we should try to understand why Trump got the support he did. From what I can see, two of the big factors were anti-establishment sentiment and just how divided America has become.
That and he promised to bring some measure of prosperity back to the lower classes, especially the rural poor. Now that US manufacturing is uncompetitive, those who live in the country and aren't farmers have basically no opportunities. There's fast food, and that's about it. Between that and the high cost of living in cities making it nearly impossible for those people to simple move there, they're pretty much trapped in poverty with no way out. It used to be the case that small towns would have a factory or a mine or some other large industry that would be its primary source of wealth. Nowadays those have been mostly outsourced, and the government has done nothing to help the those who've lost their livelihoods as a result. Now, Trump comes along and is the first politician, well, ever, to not only not ignore them while throwing what's left of their livelihoods under the bus with trade deals like NAFTA, but actually promise to help them by bringing back America's manufacturing industry, it's no wonder he was so well received. "Make America Great Again" didn't mean "get rid of all the Mexicans and put the darkies back in their place", unlike what some seemed to think, it means "bring back wealth and opportunities for everyone, not just the urban elite", which ironically is what the left is supposed to be about.
Which brings me to the left, which as a whole completely missed the point and assumed that Trump supporters are all just racists, and decided that hurling insults instead of actually talking to and persuading Trump supporters would ensure a win for Clinton. Well, given that people tend not to side with those that insult them, Trump's victory is far less surprising that some people seem to think it is.
Now, if anything good can come of this, it's the left getting their shit together and realising they have to do better than ignoring their opponents when they're not hurling insults at them. That they have to make the effort to talk to Trump supporters and find out from them why they support him, instead of just assuming they're racists. What can I say, it'd be nice to see activists of my ideology (well, more so than their opponents) do a little better than a campaign of name calling, followed by literal tears when, surprise fucking surprise, they lose.
Honestly, it's shit like this that almost makes me consider going alt right, if only to not be associated with a bunch of melodramatic manchildren.