Here’s the problem – if that happens, conservative fascists can support genocides and still be voted in. In addition to all of their other appalling beliefs. And the thing is, when Republicans win, they swing the entire country to the right. It’s happened every time since Obama.
Consider too, what happened in 2020 after Clinton lost in 2016? Did the party swing hard left? Not at all. Bernie’s team helped adjust the rules for the primary to be fairer and did away with superdelegates. Still, in a head to head against Biden, he couldn’t win. And all primaries eventually winnow down to 2-3 candidates. In a ranked choice primary, Bernie wouldn’t have won even if everyone stayed in the whole time.
To swing left, you have to build continuously and gradually.