Hillary Clinton

but Kennedy was at a very dark period in his life then, much troubled by alcohol addiction, only finally helped by second wife Victoria Reggie (although one son disagrees with that take).

Also Kennedy, unlike any other Dem candidate ever, had had two brothers assassinated while in or seeking the Office of President and he didn't get along with President Carter generally. It was not so much his lack of endorsement as his primarying a sitting President in the first place that was problematic. He did finally endorse and campaign for Carter, but things like the 1980 Moscow Olympic Boycott and especially the ongoing Iran Hostage Crisis that ABC News - oh so helpfully - featured EVERY SINGLE NIGHT, were more determinative of the outcome of the 1980 election. See., e.g., https://en.wikipedia.org/wiki/Nightline#The_Iran_Crisis.E2.80.93America_Held_Hostage_.281979.29

I'm not excusing Kennedy's behavior so much as explaining why it may have happened.

And SBS is not now, never has been and never will be a Ted Kennedy.