Matthews has a conspiratorial mindset about Cheney, from my observation. He is ALWAYS seeking an interpretation of events that has Cheney being the manipulator of Bush behind the scenes. Or has Cheney being ultimately responsible for anything the Libs don't like, or the Libs make up, about the Administration. He has Cheney on the brain disease. So he probably thinks there is some kind of secret plan for Cheney to become Bush's heir, despite all denials and evidence to the contrary.
From what I saw tonight, you are absolutely right.