Day two of the House of Representatives’ public impeachment started off with a bang, with president Donald Trump playing a key role.
On Wednesday, it was disclosure of an overheard phone call between Donald Trump and US Ambassador to the EU Gordon Sondland during which the president may have asked about Ukrainian investigations.
Friday’s big developments included the White House release of a contradictory readout of the Mr Trump’s first phone call with Ukrainian President Volodymyr Zelensky and a presidential tweet that had Republicans in Congress scrambling.
Just over an hour into Marie Yovanovitch’s testimony, Mr Trump launched the kind of Twitter fusillade that has become a regular part of his political repertoire.
He questioned the ambassador’s competence, noted that the Ukrainian president spoke unfavourably about her and pointed out that he has the right to fire diplomats at will.
What makes the moment historic is that Committee Chair Adam Schiff gave Yovanovitch a chance to refute the president’s tweet almost in real time.
Democrats are already characterising the president’s behaviour as witness intimidation – and the latest attack by the president against one of his own government employees.
And once again, Republicans, whose reported strategy was to avoid directly impugning the reputation of a long-serving, well respected diplomat, find a president who has changed the rules of engagement on the fly.
“I disagree with the tweet,” Republican congresswoman Elise Stefank told a reporter during a break in the hearing. “I think Ambassador Yovanovitch is a public servant, like many of our public servants in the foreign service.”
Mike Conaway, another Republican on the committee, said the president’s tweet was “not something I would do”.
Mr Trump may not be in the hearing room, but consistent with his mercurial presidency so far, his presence is being felt.