On Saturday morning, former president Donald Trump’s second impeachment trial appeared to be drawing to a close in the U.S. Senate. The House managers had brilliantly prosecuted their case, and Trump’s counsel had wrapped up what defense they could muster. The lone outstanding question was whether witnesses would be called. While most observers — including many senators — believed the answer would be no, a Friday night statement from a Republican congresswoman changed the calculus.

Rep. Jaime Herrera Beutler (R-Wash.) provided information about a heated phone conversation that Trump had with House Minority Leader Kevin McCarthy (R-Calif.) in the middle of the riot, which shed light on whether Trump had been aware of the immediate danger to then-Vice President Mike Pence during the mob attack on the Capitol.

“Well, Kevin, I guess these people are more upset about the election than you are,” Trump reportedly said when McCarthy angrily told him that he needed to call off his supporters. Recognizing that Herrera Beutler’s testimony about that phone conversation might add a dimension to the evidence, Rep. Jamie B. Raskin (D-Md.), the lead impeachment manager, stood in the well of the Senate on Saturday morning and requested that she be called as a witness. The Senate voted yes. But the House managers stood down after it was stipulated that Herrera Beutler’s statement be made part of the record. No witnesses were called. The Senate voted to acquit Trump of inciting insurrection — with 43 not-guilty votes, failing to reach the 67 votes needed for a conviction.

Based on what we now know, the House managers made the right call. The problem was not that they decided against witnesses. The Herrera Beutler statement bolstered what was already a strong case. Additional witnesses almost certainly would not have changed the outcome. Too many Republican senators had already made up their minds not to cross Trump — or his supporters — based largely on technical arguments unrelated to the overwhelming evidence of Trump’s guilt.

Instead, the problem is what the decision highlighted: that witness intimidation was yet again a factor in a proceeding intended to hold Trump accountable for his misconduct. Trump had tried to influence potential witnesses during the special counsel’s investigation; he had intimidated witnesses in his first impeachment; and at least one surrogate appeared to be engaged in witness intimidation this time around. Given this track record, it’s reasonable to worry that such intimidation will come into play in the various investigations now circling Trump.

Some lawmakers said former president Donald Trump’s political future was over on Feb. 14, one day after the Senate acquitted him for the second time in a year. (JM Rieger/The Washington Post)

After the trial, House managers indicated that Republican members of Congress and individuals close to Trump and Pence had refused to cooperate for fear of retaliation and retribution. On Twitter, Herrera Beutler’s fellow Republican congresswoman, Marjorie Taylor Greene (Ga.), wrote what could be read as a thinly veiled threat to Herrera Beutler, invoking Trump supporters, some of whom had stormed the Capitol. “First voting to impeach innocent President Trump, then yapping to the press and throwing @GOPLeader under the bus,” Greene wrote. “The Trump loyal 75 million are watching.

Herrera Beutler has not spoken publicly since issuing her statement on Friday night, so we don’t know if there were specific threats to her safety. But Republicans who crossed Trump after he lost the November election — such as Georgia Secretary of State Brad Raffensperger — have received threats against themselves and, in some instances, their families. Before the election, the FBI arrested a number of people on charges they had conspired to kidnap and potentially injure the Democratic governor of Michigan, Gretchen Whitmer, a frequent target of Trump’s insults. Trump’s inflammatory rhetoric notoriously caused Georgia election official Gabriel Sterling to warn that it would result in violence, after which Sterling, too, received death threats.

Trump’s propensity for witness tampering, intimidation and retaliation is well known and began long before the 2020 election. During his first impeachment inquiry, he threatened the whistleblower on Ukraine and attacked Lt. Col. Alexander Vindman, among others, ultimately retaliating against Vindman (and his twin brother) for testifying pursuant to a congressional subpoena. Trump even went so far as to try to intimidate former Ukraine ambassador Marie Yovanovitch during her public testimony before Congress. In addition, the Mueller report documented Trump’s effort to intimidate former Trump lawyer Michael Cohen after he decided to cooperate with authorities.

The violence on Jan. 6 places Trump’s threats in a different light. His “Stop the Steal” campaign has created a loosely coordinated group of domestic terrorist organizations ready to inflict harm at his command. He may have lost the ability to issue a mean tweet, but his threats now come with violent supporters appended to them.

To be clear, in this second impeachment trial, the House managers did not need any witnesses in light of their devastating presentation of the evidence that ultimately convinced 57 senators — as well as others, including Sen. Mitch McConnell, the GOP leader, who voted to acquit on what he said were constitutional grounds — that Trump was primarily responsible for the insurrection.

Just as in a bank robbery case where surveillance cameras provide video of the actual event, the real-time text, audio and video we saw of the Capitol riot is better evidence than any individual witness’s description could be.

We also saw powerful evidence of prior examples of Trump’s rhetoric leading his supporters to engage in violence, and of Trump endorsing his supporters’ violence. Trump organized the rally on Jan. 6 — a date and time specifically chosen to coincide with Congress’s certification of the electoral college vote — knew about his supporters’ plans to go to the Capitol, and incited a mob with a known propensity for violence to march on the Capitol. The ensuing insurrection was entirely foreseeable in light of the months-long effort to overturn the election and other instances of Trump’s inciting his supporters to use violence. No witness testimony would do more to establish Trump’s knowledge and intent than his own campaign to overturn the election in conjunction with his endorsement of violence from his supporters during that campaign.

And if there was any doubt about Trump’s central role on Jan. 6, the protesters themselves made clear in social media videos and law enforcement interviews that they were acting at Trump’s command. Moreover, numerous current and former Republican officials stated that Trump was the only person who could stop the insurrection — clear proof that the mob was acting at Trump’s direction. Further testimony from them was neither necessary nor advisable if they refused to cooperate with House managers to indicate what they would say and promise not to pursue litigation to avoid testifying.

Yet there was no evidence describing firsthand accounts of Trump’s advance knowledge of the violent intentions of his supporters or of his reaction to the mob. Trump had refused an invitation to testify at his trial, so it was natural and appropriate for House managers to try to identify witnesses who could provide direct evidence of his state of mind — other Republican members of Congress and officials close to Trump and Pence. Herrera Beutler courageously stepped forward to declare what she knew. But the fact that similarly situated witnesses were apparently unwilling or afraid to cooperate undermined the entire proceeding.

In the aftermath of the Capitol riot led by armed groups operating at Trump’s direction, the former president’s words and threats take on new meaning. Threats of violence are no longer abstract. With this backdrop, Trump’s consistent record of intimidation is cause for grave concern to any other mechanisms intended to hold him accountable in the future.