Trump investigation: Who is Don McGahn, and why is his testimony so important?

Donald Trump has been in legal trouble since before he became president – and now that he’s left the White House for his cloistered post-presidential existence, his troubles with the law are only deepening.

Public attention is particularly focused on the New York authorities’ multi-pronged investigation into his business dealings and financial affairs. Manhattan District Attorney Cyrus Vance last month convened a grand jury to decide whether to indict Mr Trump or people close to him.

However, other slow-burning investigations into the former president are still rumbling on. And now, one of the most important is about to hear from a crucial witness after two years trying to pin him down.

The House Judiciary Committee has for two years been investigating whether or not Mr Trump obstructed justice in his attempts to punish his perceived enemies and his efforts to thwart the investigation into possible collusion between his campaign and the Russian government. This investigation was stymied by the Trump administration’s steadfast refusal to comply with subpoenas for testimony, but now a breakthrough has been made.

On 4 June, the committee will question Don McGahn, a veteran of the first Trump campaign who served as White House Counsel until he resigned in August 2018. As reported at the time, he left the administration after Mr Trump pushed for the Justice Department to investigate James Comey and Hillary Clinton, both of whom were objects of obsession by the then-president despite a lack of evidence for his various accusations against them – accusations that ranged from the tenuous to the bizarre.

According to the Mueller report, Mr McGahn is reported to have pushed back against Mr Trump’s demands that his political enemies be targeted by the department. As the report put it wrote, the then-counsel – “a credible witness with no motive to lie or exaggerate” – recalled clearly that the president told him to relay to the deputy attorney general that “Mueller has to go”.

In fact, according to Mr Mueller, the president was so clear in his demands that the special counsel be fired that Mr McGahn nearly resigned in 2017.

“McGahn decided to quit because he did not want to participate in events that he described as akin to the Saturday Night Massacre,” reads the report. “He called his lawyer, drove to the White House, packed up his office, prepared to submit a resignation letter with his chief of staff, told [then-chief of staff Reince] Priebus that the President had asked him to “do crazy shit,” and informed Priebus and Bannon that he was leaving.”

However, unlike many in the ex-president’s orbit who were cast out and vilified when they declined to do his bidding, Mr McGahn has not so far turned on Mr Trump in public. And along with the Trump administration and its survivors, he has fought back against demands from the House committee to tell them what he knows about Mr Trump’s conduct.

Thanks largely to the change of administration and a change in the Justice Department’s position, an agreement has now been struck under which Mr McGahn will testify to the committee, but in a closed session away from prying cameras. According to the deal, he will only be asked questions about information attributed to him in the unredacted sections of Robert Mueller’s report – not an overly restrictive remit given his name appears hundreds of times in the publicly available document, and given he was questioned by Mr Mueller for around 30 hours in total.

When the deal to question Mr McGahn was reached in May, Judiciary Committee chairman Jerrold Nadler celebrated it as a step back toward legal normalcy after the aberrations of the Trump years. “When the former president vowed to fight ‘all of the subpoenas’ aimed at his administration,” the chairman said in a statement, “he began a dangerous campaign of unprecedented obstruction. We begin to bring that era of obstruction to an end today.”