Democrats in Congress will begin Monday morning to sharpen their focus on what President Trump was doing in the runup to the January 6, 2021, riot. That was the signal at the end of the first two hours of hearings Thursday, when graphic video of the violence was screened.

There was certainly no burying the lead on Thursday. The chairman of the House Select Committee to Investigate the January 6 Attack, Congressman Bennie Thompson of Mississippi, proclaimed flatly that Mr. Trump “was at the center of this conspiracy.” 

For two hours, across every major television network save Fox, that thesis was pursued with multimedia vigor. It will be difficult to go back to hearings as usual after this, a congressional presentation with the smooth flow and clever construction of a documentary. 

From a podium in the Cannon House Office Building, Mr. Thompson served as a master of ceremonies, seeking not so much to monopolize attention as to conduct an orchestra of recorded interviews and videotaped footage.  

The voices beamed to millions included intimates of Mr. Trump such as a one-time attorney general, William Barr, as well as a Capitol police officer, Caroline Edwards. She recalled: “I was slipping on people’s blood. It was carnage. It was chaos.” 

One of Mr. Trump’s primary antagonists, Representative Elizabeth Cheney, argued that he “engaged in a massive effort to spread false and fraudulent information to convince huge portions of the U.S. population that fraud had stolen the election.”

Mrs. Cheney also testified to the chasm that had opened up between Mr. Trump and Vice President Pence in the post-election maelstrom. “Maybe our supporters have the right idea,” Mr. Trump is reported to have said, when he learnt of intentions to hang Mr. Pence.

It is no surprise that this first night of hearings took the shape of a well crafted opening statement. The committee has retained more than a dozen prosecutors, well versed in the choreography of building a case. Axios reported that the Justice Department, in its budget unveiled in March, requested 131 more prosecutors to assist in its pursuit of those involved in the chaos of January 6.        

An attorney — Stanley Brand — who once served as a top lawyer for the House and now represents one of Mr. Trump’s aides, Dan Scavino, in connection with the committee’s work, told the New York Times that “this is the mother of all investigations and a quantum leap for Congress in a way I’ve never seen before.”

Unlike a trial, Thursday’s hearing, and those that will follow it in the coming weeks, featured no rebuttal, no opposing case or cross-examination. The committee is composed entirely of Democrats, save for Mrs. Cheney and Representative Adam Kinzinger, who is not running for re-election. 

It did not necessarily have to be thus. The resolution that chartered the committee empowered the House speaker, Nancy Pelosi, to select eight members and the minority leader, Kevin McCarthy, to choose five.

Mr. McCarthy in turn selected, among others, Representatives James Banks and James Jordan, both of whom have been vociferous supporters of Mr. Trump and allies in his efforts to question the 2020 election. Messrs. McCarthy and Jordan would eventually be subpoenaed by the committee. 

Mrs. Pelos rejected those suggestions, at which point the Republican caucus withdrew its cooperation. That led Mrs. Pelosi to Mrs. Cheney and Mr. Kizinger, two figures at loggerheads with their Republican colleagues. 

If Republicans hope to tell their side of the story, they will have to do it from the sidelines. Mr. McCarthy undertook that effort in a press conference Thursday morning, asserting that the investigation is being undertaken by “the least legitimate committee in American history.” 

That note was picked up by television host Tucker Carlson, who described his own show as “the only hour on an American news channel that will not be carrying the propaganda lie.”

The next hearing, scheduled for Monday morning, is meant to focus on Mr Trump’s work to undo the election prior to January 6, what the committee calls “an effort to subvert democracy.” 

After the cameras clicked off, the question remains: Will America tune in as that argument unspools, or have they already made up their minds on questions of guilt and innocence long before closing arguments arrive?