I think you’re right about McConnell’s larger intention. But it’s a yuge longshot. If Moore goes down hard, Bannon and Breitbart News might take a hit, but they’d recover quickly.
They've accused Moore of propositioning under-aged girls. I can't think of a much worse crime to be accused of from a political career standpoint. If they succeed in bringing Moore down and planting a permanent pedophile label on him, then Bannon and Brietbart will always be known as the group that backed a child molester. That will wreck them as a candidate support organization. McConnell would love that.