But their "witness list" includes individuals that were not interviewed by the House in their Impeachment inquiry, therefore they do not know what the witnesses may or may not know.
They are attempting to perform more investigation, not to prosecute the case that has been investigated by the House.
Oh, the dems know that the witnesses will have to say when questioned. The dems have had their buddies at the FBI and NSA monitoring them all along. This is the surprise evidence that the dems are alluding to. They already possess recordings and emails.