Because Al Franken apologizes have taunted her name in defending a sexual assaulter against a brave women who dared to tell the truth about her senatorial colleague. Just look at the hatred some Democrats have for her that are not due to ideological reasons but petty bitterness, where she went against the grain by asking Franken to resign his seat, therefore sparking rage among the crowd that has turned on her since. Sad to see such misogyny being displaced in our Democratic Party.
Franken was just the excuse. I think many Democrats already saw her as a craven opportunist and her statement about Bill Clinton did nothing to dispel that notion, as mentioned.
It's difficult to help and support somebody when he has a history of throwing under the bus friends and colleagues for personal political gain.