Having heard all the witness testimony in the impeachment case against Donald Trump, Congress began arguments on Monday on what that testimony meant. It did not go smoothly.

Jerry Nadler, the Democratic chair of the House judiciary committee, had barely begun introducing the session when a bearded young man got up from the public seats at the back of the chamber and started yelling.

“Americans are sick of your impeachment scam! Trump is innocent!” he shouted. “You’re the one committing treason. America is done with this!”

As uniformed Capitol policeman began ushering him from the chamber, he declared: “You can kick me out, but he’s the one committing crimes.”

There is a long history of protesters at congressional hearings, but this was no ordinary member of the public. He was Owen Shroyer, who works as a host at the far-right conspiracy site Infowars.

Shroyer was active in spreading the most bizarre conspiracy theory of the 2016 presidential election, that Hillary Clinton was running a pedophile ring through a string of pizza restaurants. The spreading of the fabricated allegations led to staff at the targeted restaurants being subjected to threats and harassment, and an armed man turning up at a Washington pizzeria with an AR-15 assault rifle in December 2016, threatening staff and shooting off the lock of a cupboard, supposedly in pursuit of an a personal “investigation” into the pedophile claims.

The gunman was sentenced to four years in jail. Shroyer is clearly still in business. His Twitter account recorded his arrest, pushing the hashtag #FreeOwenShroyer.

Shroyer’s disruption was not just an incidental disturbance, but an opening salvo in the real battle underlying the impeachment hearings: a battle over the power to shape reality.

Shroyer is on the leading edge of an effort to create a parallel universe, conjured up from a constantly replenished cloud of fabrications. The pizzeria gunman incident demonstrated the real-world consequences of an invented reality.

The aim now is to insulate Donald Trump from damaging facts – so that he could ultimately, as he has boasted, shoot someone on New York’s Fifth Avenue and get away with it. The Republican strategy in Congress is to fight on two fronts, arguing the facts of impeachment while at the same time pursuing a disinformation campaign promoting a conspiracy theory that secret Clinton emails had been hidden on an internet server located somewhere in Ukraine.

The theory betrays a lack of a basic understanding of how the internet works, and has been rejected as baseless by the US intelligence community and the president’s own former homeland security adviser, Tom Bossert.

The Republicans also pursued a hybrid approach inside the hearing room: seeking to disrupt the hearings, and when that failed, resorting to legal argument. Behind the Republican bench, party operatives set up placards that sought to make an issue of the absence of the lead Democratic investigator, Adam Schiff. One striking 4ft high poster showed Schiff in a “Missing” notice on the side of a carton of milk, in the space used normally for the photos of lost children. As chair of another panel, the House intelligence committee, Schiff was not supposed to be there, but the posters helped foment a sense of conspiracy around the hearings.

The ‘Missing’ notice featuring Adam Schiff. Photograph: Jim Watson/AFP via Getty Images

As Monday’s hearing continued, the Republican members repeatedly tried to drown out Nadler’s remarks and loosen his grip on proceedings, shouting out points of order, and then demanding a rollcall vote on them. The repeated votes, requiring each committee member to voice an aye or nay, ensured that they all remained in the chamber throughout the hearing.

One of the points of order, raised by Mike Johnson of Louisiana, complained that the argument of the majority counsel, the lawyer making the case against Trump, “impugns the motives of the president”, and therefore represented a violation of parliamentary rules – ignoring the fact that that is precisely what impeachment is all about.

The Republicans brought out their point orders and parliamentary challenges in casading volleys and Nadler – a 72-year-old congressional veteran – struggled at times to fend them off, hammering away with his gavel, his authority teetering at times before he ultimately steadied himself.

The substance of the hearing brought little, if any, new information to light. They represented a summary of the arguments made during the earlier hearings held by the House intelligence committee, that Trump used the power of his office to put pressure on the Ukrainian government to investigate his political opponents.

While the Democrats emphasised the import of the moment, with the fate of the republic at stake, the Republicans sought when possible, to make light of the proceedings as a distraction from the looming election campaign.

The minority counsel, Stephen Castor, arrived in the chamber with his papers in a large green supermarket bag, emblazoned with the words: “Live, eat, shop, reuse.” He put it on the witness table as press cameras swarmed around it. On a hearing suffused with recycled talking points, it had as good a chance as anything of becoming the defining image of the day.