If the witness vote succeeds, Hawley aims to force votes on subpoenas for House Intelligence Chairman Schiff (D-Calif.), Vice President Biden, Hunter Biden, Intelligence Community Inspector General Michael Atkinson, the still-unnamed whistleblower who reported Trump's July call with the Ukrainian president and a reported acquaintance of the whistleblower's.

White House counsel Pat Cipollone hinted at a Schiff subpoena during testimony before the Senate on Saturday by noting he didn’t appear before the House Judiciary Committee hearing on impeachment.

Democrats already forced votes to subpoena acting White House chief of staff Mick Mulvaney, former national security adviser John Bolton, and documents related to the administration's decision-making on aid to Ukraine earlier this week, all of which failed on party lines. Democrats say that the Bidens aren't relevant to the investigation.

Hawley would also seek communications among the whistleblower, Schiff and his staff, transcripts of Atkinson's congressional testimony, communications between the House impeachment managers and Democratic presidential candidates as well as documents related to Biden's drive to oust former Ukrainian prosecutor Viktor Shokin. Shokin was deeply unpopular with Western officials, who viewed him as corrupt.

There’s no evidence Biden used his position as vice president to benefit his son's work with Burisma.

Sen. Lindsey Graham (R-S.C.) said this week he'd rather request an outside counsel investigation in the Bidens than see Congress subpoena them.

A simple majority would be required to consider new evidence next week, but most Republicans oppose the measure and Democrats are currently short the four Republicans they need to win the vote. Several Republican senators are undecided.

Likewise, 51 senators would be required to win votes on issuing subpoenas for additional documents and witnesses.

