I always felt that partisan's from both sides of the aisle always fail to see the reality of the big picture. They're seeing the world through either deep red or deep blue colored glasses. In 2016 it really didn't matter the reasons why Clinton was disliked, what was needed was to acknowledge that and move on to a candidate that was seen in a more positive light by America as a whole. I personally think that in 2016 Hillary was disliked because she came across to the less to non-partisan folks as aloof, elitist and fake. One has to remember that for most independents, the less to non-partisans they don't follow politics, the daily grind at all. Most don't become much interested in politics until an election approaches. They're busy with their daily lives, rooting for the favorite sports team and watching their favorite TV show. Politics is something way down the list for them. The reason is simple, they don't have a horse in the race. So they go by their feelings when it comes time to begin paying attention.
So even if it were 30 years of mudslinging, most of the less to non-partisans, the independents probably never heard of 29 and a half years of it. What they saw as an obnocious, uncouth, unmannered, raunchy candidate vs. a fake, an elitist, one heck of an aloof individual. This is why 54% of all independents, the non-affiliated, less to non-partisan's disliked both major party candidates. Their perspective of both was both sucked which resulted in 12% of those folks voting against both.
I'm not a partisan, both major parties disgust me to no end. I like to think of myself as a political realist. Cold hard numbers, cold hard numbers especially if one delves deep into them can explain a lot of things. The explanations that the partisan folks don't want to hear, most won't even acknowledge the facts or if they do, come up with excuses.
The numbers tell me that Clinton was disliked by the way she acted and came across to the people, especially those who pay little to no attention to politics. That was their perspective of her, how they felt about her. Of course Democrats would love her, Republicans would hate her, the rest go by individual perceptions of what they see and hear, how she acts and comes across to them. Aloof, elitist, fake are the three most utilized words expressed by the non-affiliated, less to non-partisan, independent group of voters. They arrived at that perspective of Clinton from what they seen probably from June 2016 through Nov 2016. Not from 30 years as they weren't even paying any attention to her then.