The question was, would Donald Trump go there? Of course he would.

The presidential pardoning of a Thanksgiving turkey dates back 30 years. Barack Obama used to embarrass his daughters with “dad jokes” and puns for the ages such as “Yes, we cran”.

Those were innocent times. Trump is under the cloud of an impeachment inquiry and, even as guests gathered in the White House Rose Garden on a beautifully crisp autumn day, the House of Representatives’ judiciary committee announced a hearing for next week.

So when the current president emerged from the Oval Office with the first lady, Melania Trump, but not his children, he faced a dilemma of tone and whether to make light of the looming charges of high crimes and misdemeanours as he talked about Bread and Butter, the names of this year’s turkeys, from North Carolina. Trump being Trump, he dived in.

“Thankfully, Bread and Butter have been specially raised … to remain calm under any condition, which will be very important because they’ve already received subpoenas to appear in Adam Schiff’s basement on Thursday,” Trump said. “It’s true. Hundreds of people have.”

Butter walks in the Rose Garden before the pardoning ceremony. Photograph: Evan Vucci/AP

There was laughter and applause from guests on the front row including the acting chief of staff, Mick Mulvaney. During the House intelligence committee hearings this month, chaired by Schiff, Republicans made much of the fact that closed-door depositions took place in a “basement”, as if this made them especially sinister.

Yet there was also something jarring about Trump, who has been described as a combination of would-be dictator and low-rent lounge act, turning an alleged attempt to abuse his office and bribe Ukraine for political gain into a laugh line.

And he was just warming up. “It seems the Democrats are accusing me of being too soft on Turkey,” he said, deploying a pun regarding his abandonment of Kurdish allies to inevitable slaughter.

“But Bread and Butter, I should note, that unlike previous witnesses, you and I have actually met. It’s very unusual.” More audience laughter, though Trump himself almost never laughs in public. “In any event, I expect this pardon will be a very popular one with the media. After all, turkeys are closely related to vultures.”

One of the turkeys walks in the Rose Garden while Donald Trump speaks with Melania by his side. Photograph: Tom Brenner/Reuters

Then, as so often during his campaign speeches, Trump broke the fourth wall by commenting on his teleprompter speech in real time: “I don’t know if I like that line, but there is a little truth to it.”

In another strange segue hardly in keeping with a jovial festive occasion, Trump so reminded everyone of his military’s firepower and hunt for enemies. “We captured the number one terrorist in the world and killed the number one terrorist in the world, al-Baghdadi.”

Finally he got back to talking turkey. Bread and Butter will be on display for visitors at their permanent home at Virginia Tech’s Gobblers Rest exhibit. “Oh, that looks like a dangerous bird,” he said as Butter ran on the lawn. “It just escaped.”

The 47-pound creature was lifted back on to a table as Trump and Melania walked over. There was a laying on of hand. “Butter, I wish you a lot of luck! I hereby grant you a full and complete pardon.”

It would have been music to the ears of Roger Stone.