I think the worst that this'll lead to, in the short term and on a large scale, is a cementing of the divide. Once it's called, they'll back down and try to prevent losing the runoffs. Their gameplan after that will probably be a continued disinformation campaign, aiming for a red wave in 2022 and a Republican president in 2024. They may even embark on a "false narrative" campaign later, aiming to change people's minds about what happened.

Also, with the SCOTUS on their side, they probably feel "cautiously optimistic" about 2 years with a Democratic president and House - maybe even with a Democratic president, House, and Senate. I expect a lot of challenges to any substantial legislation, especially if progressive.