I think that the Democratic Party lost due to a myriad of reasons. Hubris being one of them. The Democrats ran the most establishment candidate possible at a time when the country was clamoring for something far different than what we have ever had. The country was sick and tired of repeats and blasts from the past. We certainly didn't want another legacy candidate, that's what Hillary Clinton represented. People were wanting real change. That's why populist candidates saw the biggest rallies and had throngs of supporters.
Hillary Clinton racked up a lot of pledged delegates against Bernie Sanders' insurgent campaign, the problem is that the Dems refused to take the blinders off. Hillary Clinton won states that would NEVER go for a democrat. Their biggest mistake was to not look at Michigan as an outlier. She have had my home state by the 40 point lead she began with but Bernie won it anyway. People like to say that she won more votes, while not taking into account all of the states that have caucuses instead of ballot voting.
Part of what won Trump the presidency was the sheer ignorance and lack of understanding of the Democratic party and the racist, sexist, xenophobic past of America coming back to haunt itself. It really never went anywhere, it was just hidden. By my estimation Trump won with 50% died in wool Republicans, 25% Independents/Democrats, and 25% Basket of deplorable. The truth of the matter is that there are people in this country who voted for Trump who actually believe that slavery should never have ended. While it is untenable for most Americans that others believe something and despicable as this, it's true. There are those that voted for Obama but still voted for Trump because they wanted to see someone who was looking out for them. He talked a good game, but unfortunately those people believed in all the talk instead of looking at the life he's lived for decades. Nothing in his background says that he supports the little guy. In fact it says the opposite. But in this day and age of reality shows and everyone wanting to live the lifestyles of the rich and famous this was to be expected.
How do we move forward though?
Make your suggestion in the comments section. I think working together this ill fated election could make a more positive impact than we could have ever imagined.