Al Schmidt, the only Republican official in Philadelphia to oversee voting during the 2020 presidential election, on Monday told the congressional committee investigating the Jan. 6, 2021, attack on the Capitol that with a single tweet, then-President Donald Trump unleashed a barrage of death threats against him and his family because of his refusal to back Trump’s false fraud claims.

The menacing threats, Schmidt said, came after a Nov. 11, 2020, tweet in which Trump referred to him as a “RINO” — a Republican In Name Only — and a “disaster on the massive election fraud and irregularities which took place in Philadelphia.”

“The threats prior to that tweet … were pretty general in nature,” Schmidt told the committee. After Trump’s tweet, Schmidt said, “the threats became much more specific, much more graphic.”

One message sent to a family member threatened to fatally shoot them and their children. “Heads on spikes. Treasonous Schmidts,” read the message, a screenshot of which appeared during his testimony.

Schmidt’s testimony during the committee’s second public hearing came as members sought to demonstrate Trump’s power to incite supporters to violence through his Twitter account. That argument is central to their case that there is a direct line between the lies Trump proliferated on the social media platform and the deadly attack on the Capitol.

Other witnesses testifying Monday made clear that numerous advisers had told Trump that claims of widespread fraud in Pennsylvania and other battleground states were meritless, and that he had legitimately lost.

And yet, he persisted in maintaining the election had been stolen from him.

His former attorney general, Bill Barr, said in videotaped testimony that he worried the president had become increasingly “detached from reality.” Barr called a specific claim, repeated by Trump and his supporters, that more people voted in Philadelphia in 2020 than there were registered voters, “absolutely rubbish.”

“The turnout in Philadelphia was absolutely in line with the rest of Pennsylvania,” Barr said. “There was nothing strange about the Philadelphia turnout.”

» READ MORE: Scott Perry, Philly Proud Boys, and more: Pa. had a starring role in the first Jan. 6 committee hearing

Also false, Schmidt said, was a claim repeated by Trump allies that ballots in the names of some 8,000 dead people were cast that year. After investigating, Schmidt said, officials didn’t even find eight instances of that happening.

“We took seriously every case that was referred to us,” he said, “no matter how fantastical, no matter how absurd.”

Schmidt, who in January left his post as one of three city commissioners who oversee local elections, has been a vocal defender of the legitimacy of elections since the 2020 vote, and has broken with his party on numerous occasions to call out Trump’s false claims of fraud.

When Schmidt was asked on CNN in the weeks after the election what he would tell Trump, he responded: “I think people should be mindful that there are bad actors who are lying to them.”

Within minutes, Trump shot back on Twitter that Schmidt “is being used big time by the Fake News Media to explain how honest things were with respect to the election in Philadelphia. He refuses to look at the mountain of corruption & dishonesty. We win!”

No Republican official in Pennsylvania offered support for Schmidt as Trump and his supporters launched attacks against him. He has previously described the behavior of some Trump supporters in the postelection period as “very deranged.”

Before leaving office, Schmidt, who now leads the good-government watchdog group Committee of Seventy, stressed that his decision wasn’t driven by the attacks from Trump and his supporters.

“That would be like capitulating to the psychological terrorists, which was their point — or else, I’d leave today,” he told The Inquirer at the time.

Other witnesses who testified before the committee Monday included Republican elections attorney Benjamin Ginsberg; BJay Pak, a former U.S. attorney in Georgia; and Chris Stirewalt, a former Fox News political editor who left that job amid controversy after accurately calling that Trump had lost Arizona to Joe Biden.

Bill Stepien, Trump’s campaign chief and a former adviser to former New Jersey Gov. Chris Christie, had also been scheduled to testify Monday, but withdrew at the last minute because his wife went into labor. Committee staff said they may reschedule his testimony for another date.