[King:] This important news just in to CNN, the House Oversight Committee now set to issue a subpoena to the Postmaster General Louis DeJoy demanding documents the Committee says he is refusing to give Congress. You might remember, DeJoy recently grilled by lawmakers on controversial changes at the Postal Service changes many of these lawmakers worry will impact mail-in voting this fall. CNN's Kristen Holmes is tracking this story. So Kristen, a subpoena going to the Postmaster General, what the House Democrats say he is refusing to give up?
[Kristen Holmes, Cnn National Correspondent:] Well, remember on Monday, John, you just talked about this grilling. The Postmaster General was pressed by multiple members to provide documents on the changes that he's made to the postal service that have caused these widespread delays. Now, on top of that, they're also seeking documents on how this could potentially impact the election, as well as any communication that DeJoy has had with the Trump campaign that's on Monday. DeJoy revealed that he had been in touch with friends on the campaign about Donald Trump's rhetoric surrounding mail-in voting, saying that it was not helpful. So now the Committee is seeking any sort of communication that he had. So they set this deadline for Wednesday. Two days after that, we are told from a source close to the Committee that he had not provided any documents but instead sent a letter that said, quote, I trust my August 24th testimony before the Committee on Oversight and Reform clarified any outstanding questions that you had. One thing to note is that I talked to the Postal Service this morning. He told me they would be responding to the Committee, but clearly here they were parsing words saying this response it's actually something that came last Friday, but it doesn't seem that they have any intent on turning over these documents. Now the subpoena is set to be issued on Wednesday, John?
[King:] On Wednesday escalating standoff between the Postmaster General and House Democrats. Kristen Holmes, appreciate the breaking news. We'll stay on top of the story as it continues and it will, again, when it comes to mail-in voting, some voters can start doing that in just a couple of weeks, so very important questions. Coming up for us, a coronavirus vaccine could be approved before the final trials are over. Some experts worry about that.