As lawmakers ready a Thursday vote to send a contempt referral to the U.S. attorney's office in Washington, there's considerable uncertainty about whether the Justice Department will prosecute Bannon for refusing to cooperate with the investigation into the Jan. 6 insurrection, despite Democratic demands for action.

The outcome could determine not only the effectiveness of the House investigation, but the strength of Congress' power to call witnesses and demand information — factors that will certainly be weighing on Justice officials as they determine whether to move forward. While the department has historically been reticent to use its prosecution power against witnesses found in contempt of Congress, the circumstances are exceptional as lawmakers investigate the worst attack on the U.S. Capitol in two centuries.