Chairman Bennie Thompson has gaveled in the committee's first prime-time hearing intended to "remind you of the reality of what happened that day."

"But our work must do much more than just look backwards. Because our democracy remains in danger," Thompson will say in his opening statement, according to an excerpt released by the committee. "The conspiracy to thwart the will of the people is not over."

Americans will hear live testimony from a Capitol Police officer and documentarian who were on the scene of the attack and watch never-before-seen video footage in a rare congressional hearing made for television.

Rep. Liz Cheney, R-Wyo., vice chair of the select committee, was the first member to arrive on Capitol Hill through the member entrance, according to an NBC pool reporter.

Asked how she was feeling, Cheney said, "Good, thank you," as she walked inside.

Cheney and Rep. Adam Kinzinger, R-Ill., the only other House Republican to accept a seat on the panel, have faced relentless attacks from within their caucus for their participation. Cheney was removed from her No. 3 House GOP leadership post last year, and both were formally censured by the Republican National Committee for choosing to investigate what it controversially called "legitimate political discourse."

Demonstrators gathered outside the U.S. Capitol on Thursday ahead of the House select committee's first prime-time hearing of its Jan. 6 investigation.

Participants held signs reading, "Not above the law."

The panel is looking to explain what it calls a "coordinated, multi-step effort" by Trump and his supporters to overturn his 2020 election loss.

From legal action to name-calling, Trump continues to try to discredit the House select committee as the panel prepares to go public with its findings in prime time.

"January 6th was not simply a protest, it represented the greatest movement in the history of our Country to Make America Great Again," Trump said in a string of posts hours ahead of the hearing on Truth Social, the social media platform his team launched after Twitter permanently suspended him in the wake of the Capitol siege "due to the risk of further incitement of violence."

Click here for more on how Trump has deployed an arsenal of rhetoric to recast what happened and undermine the investigation.

Rep. Liz Cheney, R-Wyo., had a message for her colleagues who continue to defend Trump and his false election claims.

"Tonight I say this to my Republican colleagues who are defending the indefensible: There will come a day when Donald Trump is gone, but your dishonor will remain," Cheney said.

Cheney also had a message for the American people as they watch these hearings unfold over the next several weeks.

"Please remember what is at stake," she said. "Remember the men and women who have fought and died so that we can live under the rule of law and not the rule of men."