I doubt your data. Just one counter example, in Orange County CA, Katie Porter, a democrat, won a competitive seat in a district that has been Republican for a long time (maybe 30+ years?).
From what I understand, she wasn't endorsed by Our Revolution (I'm strictly talking about the Bernie-aligned groups). She was endorsed by lots of other progressive groups that are more effective at this sort of thing.
On the other hand, people like Kendra Horn flipped deep-red Oklahoma 5th with help of Bloomberg's Independence PAC, and Sharice Davids beat Bernie-backed Brent Welder in the primary to win the general by 10 points in a swing district.
Does it matter if it's a Bernie aligned group? In CA-25, Our revolution endorsed one candidate, Justice Democrats another candidate, and a third Democratic candidate actually won yet another historically Republican district. They were helped (but not endorsed) by also progressive, but not as closely aligned to Bernie, Indivisible, by loose Bernie inspired independents, etc. I think it's a mistake to only look at strict boundaries of support by candidate name. I would consider CA-25s win with Katie Hill another progressive win in an contentious district.
