And in that capacity he could serve Clinton well: His plans could be the threat, her plans the compromise. Republican Congressmen would go along with her just because he looms large over them.
Their Democratic constituents are not going to dismiss his ideas, when he almost won the primaries. That's a lot of people out there that could decide to defeat them. And if they all came out to vote, they could topple any incumbent. Their "safe" districts are not all that safe because their gerrymandering math only puts a small majority of Republicans into as many districts as they can. An abnormally large Democratic turnout could defeat that.
