Bad. Shes already losing men by wide margins.
That's exactly the point though. I doubt she has much more room to fall among white men. In a poll where she was leading by 4 she was only winning like 25% of white men, which is pretty mindblowing. It might be better to just write them off and double down on swaying white women.
I'd still prefer Kaine since he's safe and could add a point or two in crucial VA, and I don't think she needs to be risky. But Warren is a pretty good higher risk/higher reward candidate. I'd prefer her over Castro at least.