On Monday's broadcast of CNN's "OutFront," Senator Jeff Merkley (D-OR) discussed the possibility of 2020 Democratic presidential candidate former Vice President Joe Biden testifying in the Senate's impeachment trial by stating that he is trying to take an impartial approach, and "the defense needs to be able to pull in and present people that they feel have relevant information...if they think that there is value in certain witnesses to come forward, those folks should testify and be present."