at least when it comes to getting someone higher up the chain.

gates stayed with the campaign even after manafort left.
even through the transition, the inauguration, etc.
then started working at a pro-trump pac building relationships with big donors.
gates had long-time dealings with russian oligarchs like manafort as well.

you put some pressure on him, he could have dirt on more folks than manafort (and over a longer period more relevant to the trump administration).