I think republicans are also divided, although not quite so obliviously.

I think the Dems learned their lesson when hard core Bernie supporters didn't support Hillary when she won the nomination. At least Ihope so.

We should worry more about a civil war erupting in the U.S., especially if Trump refuses to step down.

Well that is sensible, just when the USA is dire need of a coherent and united oppositions to counter a political and social crisis brought about by the most abhorrent miscarriage of electoral stupidity in the nations relatively short history, the actual opposition is bickering among itself like attendees at a five years old's birthday party disagreeing over the size of the slice of birthday cake each has been given.