WATCH: Attorney General Garland testifies before House on Justice Department oversight

Attorney General Merrick Garland gave no hints during a House Judiciary Committee Thursday on what the Justice Department will do if the House votes to hold Steve Bannon in contempt of Congress.

Watch in the player above.

“If the House of Representatives votes for a referral of a contempt charge, the Department of Justice will do what it always does in such circumstances. It will apply the facts and the law and make a decision consistent with the principles of prosecution,” Garland said.

In his opening remarks the attorney general told the committee the Jan. 6 investigation is one of the most “sweeping” in Justice Department history.

“Keeping our country safe requires protecting its democratic institutions, including the one we sit in today, from violent attack.”

The House is voting Thursday on whether to hold Bannon, a longtime ally and aide to former President Donald Trump, in contempt of Congress after he defied a subpoena from a committee investigating the violent Jan. 6 Capitol insurrection.

That committee has vowed to move swiftly and forcefully to punish anyone who won’t cooperate with the probe. But it’s likely up to the Justice Department, and the courts, to determine what happens next.

If the House vote succeeds, as expected, there’s still considerable uncertainty about whether the Justice Department will prosecute Bannon, despite Democratic demands for action.

The outcome could determine not only the effectiveness of the House investigation but also 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 reluctant 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.

To emphasize the committee’s unity in holding Bannon accountable, the panel’s Democratic chairman, Mississippi Rep. Bennie Thompson, will lead the debate on the bill along with Republican Rep. Liz Cheney of Wyoming, one of two Republicans on the committee – a rare show of bipartisanship on the House floor.

Still, most House Republicans are expected to vote against the contempt measure, despite the potential consequences for the institution.

The Jan. 6 panel voted Tuesday evening to recommend the contempt charges against Bannon, citing reports that he spoke with Trump before the insurrection, promoted the protests that day and predicted there would be unrest. Members said Bannon was alone in completely defying his subpoena, while more than a dozen other witnesses were at least speaking to the panel.

Ranking member, Rep. Jim Jordan (R-OH) of the Judiciary Committee in his opening statement slammed the attorney general for not responding to Republicans letters that posed an objection to recent action by DOJ to counter threats targeting school board members, teachers and other employees in the nation’s public schools.

In a memorandum, Garland said there has been “a disturbing spike in harassment, intimidation, and threats of violence against school administrators, board members, teachers, and staff who participate in the vital work of running our nation’s public schools.”

To address the rising problem, Garland said the FBI would work with U.S. attorneys and federal, state, local, territorial and tribal authorities in each district to develop strategies against the threats.