House Speaker Mike Johnson during a joint meeting of Congress in the House of Representatives at the US Capitol in Washington, DC, on April 11.

Years before becoming House speaker, Republican Rep. Mike Johnson of Louisiana played a leading role aiding Donald Trump’s efforts to overturn the 2020 election.

That history will be on display Friday, with Johnson set to deliver remarks alongside the former president about “election integrity” – a phrase Trump often uses to describe the lie that the 2020 election was rigged and unfounded concerns about future mass voter fraud.

Johnson carved out an influential role after the 2020 election, helping Trump’s attempts to subvert the will of the people and overturn the legitimate results. Many of his actions took place behind-the-scenes or didn’t break through beyond his Louisiana district, while more prominent pro-Trump figures soaked up the post-election attention.

Like many Republicans, he questioned the legitimacy of Joe Biden’s victory and raised concerns about the expansion of mail-in voting during the Covid-19 pandemic. His gripes echoed longstanding, garden-variety GOP complaints about mail-in voting, which largely ignore the reality that there is a staggeringly tiny level of fraud in US elections.

But he also promoted perhaps the most farfetched conspiracy theory bouncing around at the time: that two voting technology companies, Smartmatic and Dominion Voting Systems, flipped millions of votes from Trump to Biden as part of an international plot.

“The allegations about these voting machines, some of them being rigged with this software by Dominion, there’s a lot of merit to that,” Johnson told a Louisiana radio station in November 2020, adding, that there was “a software system that was used all around the country, that is suspect because it came from Hugo Chávez’s Venezuela.”

These claims were false. Dominion and Smartmatic later filed defamation lawsuits against many of the pro-Trump media outlets and figures who peddled the lie, though they didn’t sue Johnson. Fox News settled with Dominion for more than $787 million.

Johnson also claimed that “in Georgia, it really was rigged” because “the system is set up for massive fraud,” even though Republican officials oversaw three statewide tallies that confirmed Biden’s razor-thin victory and did not uncover systematic irregularities.

He later recruited a majority of House Republicans to endorse a Trump-backed lawsuit seeking to invalidate the results from four key states that Trump lost: Pennsylvania, Georgia, Michigan and Wisconsin. The Supreme Court swiftly rejected the case.

The legal brief that Johnson submitted along with 125 of his fellow House Republicans, claimed that “unconstitutional irregularities involved in the 2020 presidential election cast doubt upon its outcome and the integrity of the American system of elections.”

Hours after the January 6, 2021, insurrection was quelled, when Republicans objected to the Democratic electors from Arizona and Pennsylvania, Johnson voted for the objection, which would’ve deprived Biden of 36 electoral votes that he legitimately won.

On the House floor – the scene of an armed standoff, mere hours earlier, between police officers and the pro-Trump mob – Johnson inaccurately claimed there had been  a “usurpation” of authority by judges who changed voting rules in 2020. (In truth, as the Supreme Court later affirmed, judges have the power to review state election laws.)

The longshot bid to nullify the results from Arizona and Pennsylvania, which would’ve disenfranchised 10.3 million voters, was defeated by a bipartisan majority of lawmakers.