For cabinet members resigning, it helps them avoid being part of the decision to invoke (or not invoke) the 25th amendment. Betsy can say she resigned, rather t

For cabinet members resigning, it helps them avoid being part of the decision to invoke (or not invoke) the 25th amendment. Betsy can say she resigned, rather than be faced with the decision to remove a President from office. So while not linked to Democrats at all (she was 2 weeks from losing her job anyway), resigning was politically safer.