“Our very special guest tonight is to aviator sunglasses what Tom Cruise is to aviator sunglasses,” quipped the late-night TV host Jimmy Kimmel. “I’m proud to say I voted for him dozens of times. He is the reason we all got a cavity search tonight.”

This was how Kimmel introduced Joe Biden for his first in-person interview with a late-night host since taking office as US president.

But any hopes that Biden, whose poll ratings are plunging, might have had that the comedian would invite him to show a lighter side to his personality were soon dashed. It was a night when there were not many laughs.

Once the president had sat down, Kimmel asked: “Do you mind if I ask you some serious questions?” He then dived straight in to demand why, after a flurry of mass shootings across America, nothing had been done since Biden entered the White House.

“Well, I think a lot of it’s intimidation by the NRA [National Rifle Association],” the president replied. “Look, this is not your father’s Republican party. This is a Maga party,” – a reference to the former president Donald Trump’s “Make America great again” slogan, which Biden is increasingly using an insult.

“It’s a very different Republican party and so you find people who are worried, I believe, that if they vote for a rational gun policy they’re going to be primaried and they’re going to lose in a hard-right Republican primary.”

Biden said he had always had a “straight relationship” with Mitch McConnell, the Republican minority leader in the Senate. “You know, he’s a guy that when he says something, he means it. I disagree with a lot of what he says, but he means it.”

But Kimmel, seemingly determined to blunt rightwing criticism that he would give the president an easy ride, showed greater willingness to interrupt Biden than many political interviewers. He objected that McConnell had contradicted himself on confirming supreme court justices in a president’s final year.

Biden added: “Look, he’s the leader of a party that’s moved very hard right and so, in order to get anything done, he has a different problem than he did early on before Trump became president.”

Kimmel observed that although the Republican party had moved to the hard right, the American people had not because an overwhelming majority supported expanded background checks on gun buyers. His voice quivering with emotion, the host suggested that every senator should sit with the grieving families of 19 schoolchildren killed last month in Uvalde, Texas.

He interrupted Biden again to ask impatiently: “Can’t you issue an executive order? Trump passed those out like Halloween candy.”

The president noted he had issued some executive orders but said to applause: “I don’t want to emulate Trump’s abuse of the constitution and constitutional authority.”

He said he knew some people felt like “Republicans don’t play it square, why do you play it square? Well, guess what? If we do the same thing they do, our democracy will literally be in jeopardy. Not a joke.”

Kimmel replied: “It’s like you’re playing Monopoly with somebody who won’t pass go or won’t follow any of the rules, and how do you ever make any progress if they’re not following the rules?”

Biden smiled and joked, “You’ve got to send them to jail”, a reference to a punishment in the board game.

Biden is facing concerns about high fuel prices, baby formula shortages, and a lack of progress on several legislative fronts such as gun safety and voting rights. A Morning Consult poll published on Wednesday found that 58% of those surveyed disapproved of Biden’s performance as president, while 39% of respondents approved.

Biden has also been criticised for giving fewer media interviews than his predecessors: Wednesday’s was his first since 10 February. While Trump gave late-night TV a wide berth as president, Barack Obama was a regular presence on the shows during his time in office. Biden did a virtual interview with Jimmy Fallon last December.

Kimmel’s show on the ABC network was recorded in Los Angeles, where Biden is visiting for this week’s Summit of the Americas, bringing together countries from across the hemisphere. The first lady, Jill Biden, was in the audience along with Biden’s granddaughter Naomi and her fiance.

At one point Kimmel, who in past years has spoken out passionately about healthcare and gun violence, pondered political gridlock and the spread of false information and advised: “I think you need to start yelling at people.”

Biden demurred, saying the US was still suffering from the effects of the coronavirus pandemic, but insisted he had “never been more optimistic in my life”.

Kimmel again cut in: “Why are you so optimistic? It makes no sense.”

Biden said he was pinning his hopes on young people, the “best educated, least prejudiced, most giving generation in American history. This generation is going to change everything. We just have to make sure we don’t give up.”

Later Kimmel sympathised with Biden’s endlessly multiplying crises, including an imminent supreme court decision on abortion rights. “What a terrible job you have,” he said. “I’m glad you’re doing it. But, boy oh boy, does this seem like a bad gig.”