- People are often consistent in their behavior. A man who is apparently a belligerent drunk and has retrograde views about women and says "what happens at Georgetown Prep stays at Georgetown Prep" is unlikely to have been awful to just one woman. In my voyages through academia, the guys who have been caught/accused of being sexual harassers did it not just once but repeatedly. The combination of hard-wired personality flaw (putting it mildly) and impunity tends to mean, in my limited observation, tends to lead to the person doing the same stuff over and over and over again. This could be applied to Al Franken with his form of sexual harassment--serious but not the level of sexual assault that Kavanaugh is being credibly accused of--and Bill Cosby, whose modus operandi was quite consistent. While it is possible to engage in awful behavior just once, it is unlikely.
- I wrote last year about permission structures: that situations exist that make it harder or easier to come forward. That once there is one or two accusations, people realize that they are not alone, that it is ok to come forward. What this post missed is that people may start to come forward not just because they feel that they are more likely to believed and that something might actually be done, but because they find common cause with the initial accuser and want to buttress their legitimacy with their own story.
No, it is not a smear campaign, but the opening of a Pandora's box of one's awful past behavior. Kind of hard to get closed. There are, of course, three ways to avoid this: don't do awful shit; realize and show real remorse; or avoid the national spotlight rather than feeling entitled to the highest positions in the land. Alas, those who have done awful things and have gotten away with it for years are unlikely to show real remorse or shy away from the highest offices.
[There is real social science on cascades, starting with Timur Kuran, but I am not really building on it here]