Some other interesting things to think about in your scenario:
- Hillary replaces Scalia flipping the court to 5-4 liberal majority.
- RBG retires not to long after, securing that liberal majority. Breyer may also choose to retire. The liberal court would be locked in for a long time.
- With a trifecta, it would be interesting to see what Hillary's main legislative priority would be. Infrastructure is probably a safe bet. Some Obamacare tweaks? Another try at climate legislation? Whatever is done would have to go through reconciliation.
- 2018 would be an absolute bloodbath for Democrats on a level worse than 2010 or 2014. Like Republicans get the ability to call a Constitutional Convention level bad.
- How does she handle COVID-19? What's the reaction from a Republican Congress and a supermajority of states under total Republican control.
I was just thinking about all of this and if there was no 1/6 or similar butterfly, then yes. There would probably be a really bad year for Democrats. If there was, I think 2018 is bad, but probably not as bad as a 2014 type situation and if COVID happened and Republicans did what they did and Hillary basically embraced it in a 9/11 fashion, she could have gotten another trifecta, or at least reelected. 2022 would be a major bloodbath, though.