This is the first sign that Joe Biden may drop the Uncle Joe routine for the 2020 Democratic primary and go back to being the ruthless political knife fighter that he was in the U.S. Senate.

In a CNN interview that airs Friday, Biden casually mentioned that his campaign has been collecting dirt on his 2020 primary opponents. He said he wants to focus on the issues and that he does not want to go low, but he was also sure to let slip that he knows where the bodies are buried.