But I think a lot of it is just due to her being a woman. And an older one at that.
Many people are not all that progressive in the US, as the campaign has clearly shown.
(I know she was a candidate with plenty of flaws, but a lot of dirt that got thrown at her would never have been directed at a man in that manner).
People usually vote for who they like, not for who's probably competent. Regardless of education.
It should also be mentioned that in a historically dirty campaign that focused less on what people wanted and more on whom they least wanted in office, gender, hair color and other less relevant aspect suddenly becomes more important. Obamas "Change we can believe in" and "Yes We Can" is more engaging than "I'm with her". Of 32 general election TV ads, 24 of those ads show or mention Trump. That explains to me why the left failed in this case, rather then the gender of the candidate.
I don't think the majority of Trump voters actually believe that Clinton shouldn't be president because she's a woman. They just view her as a corrupt, establishment politician and Trump just seemed like the lesser of two evils in their eyes.
I think the media vastly underreported just how much the Right hates Clinton. The Right wing media has been pushing anti-Clinton rhetoric hard for about eight years now!
/E these articles say everything better than I could. They were written in the early 2000s.
Edit: just Google image search "Trump that bitch" and tell me again gender has nothing to do with it.
1) his hair
2) his (supposed) psychological state, e.g. [1]
3) "deplorables" - we all know what and who is meant by this and very few or none of these are responsible for their situation
4) his family name
I like how Dilbert's author put it. This is why Trump won [2], or, more humorously [3]
[1] http://www.theatlantic.com/magazine/archive/2016/06/the-mind... [2] http://blog.dilbert.com/post/152293480726/the-bully-party [3] https://www.youtube.com/watch?v=sb7XaRPFPjI https://www.youtube.com/watch?v=WVKC0egDBpk and https://www.youtube.com/watch?v=dvpDwtYl5TA
But the fact that she kept highlighting her gender as a reason to vote for her probably did annoy some people.
That's one she managed to spin positively.