I'm not referring to impeaching the President; but rather sending a message. While it makes sense to have blue dogs in Purple States, there is no excuse for neoliberals in solidly blue states to retain their seats. A safe seat is a great place for a Primary that results in an Upset, since whomever the Dem nominee is will likely win. It will send a message to the permaconciliatory/neoliberal wing when one of their longstanding members is replaced by a more mainstream Democrat.
It's okay for a party to make concessions with the other party to get something done.
It's another thing when the leader of a party makes a powerful appointment that goes against the wishes of the majority of those who elected them; a breach of Faith.