was the impeachment process. Despite the fact that the media discounted the Republican innuendo about his and his son's roles in Ukraine, I think a lot of people felt that this would nonetheless be heavy baggage to counter in the general election. The innuendo alone is more than anyone wants to deal with when the objective seems to be "beat Trump" above all else. That, together, with his uneven performances in debates (although which of the candidates has not been uneven).
I have another observation that counters the general narrative that has been set up: that is, "moderate" vs. "progressive." There's another split that seemed evident to me in the first two contests: age vs. relative youth. I mean, let's be real: four of the major candidates (Biden, Sanders, Bloomberg, Warren) are in their early to late 70s; the two relatively younger candidates who rose to top level in the first two primaries are in their late 30s to late 50s (Buttigieg and Klobuchar). I think there's a younger-older split going on as well, even if people don't realize it themselves. Oddly, younger people are trending toward the oldies, while older people are trending toward the younger ones. Go figure. I think a part of it, at least for those who are older, is that they are subconsciously thinking: none of these people (like myself, or myself in a decade or so) would be hired for a top level new job (maybe they'd be put on a board of directors, but they wouldn't be chosen as the CEO running a big company), or even most any old job. It seems the only job you can go for after 60 is president!