The Republican party’s vilification of members of Congress who have criticized Donald Trump or supported bipartisan legislation is “ruining America”, New Hampshire’s governor, Chris Sununu, said on Sunday, adding another tacit voice to the small but growing internal opposition to the former president.

Sununu, seen as a rising star of the post-Trump right, attacked his colleagues in an interview on CNN, insisting that House Republicans “have their priorities screwed up” for seeking retaliation against 13 members who voted for Joe Biden’s $1.2tn infrastructure bill.

Sununu was scathing when asked about the call for those members to be stripped of their committee assignments in the same week that only two Republicans – vocal Trump critics Liz Cheney and Adam Kinzinger – voted to censure their colleague Paul Gosar for tweeting a video showing him murdering the Democratic congresswoman Alexandria Ocasio-Cortez.

“That’s kind of that social media mob mentality that’s built up in this country where we don’t agree with one issue so we’re going to attack them, we’re going to vilify one person or one individual. We’ve got to get beyond that, because culturally, it’s really, really ruining America,” he said.

“Politics in its entirety on both sides of the aisle in Washington is screwed up. They got their priorities all wrong, they focus on the wrong things. They don’t talk about balancing budgets, fixing healthcare, immigration reform, social security and Medicare … instead we spend all of our time focusing on these nitpicky things.”

He defended Cheney, who was ousted from her leadership role earlier this year by House Republicans after she challenged Trump’s lie that his election defeat by Joe Biden was fraudulent.

Regarding Republicans’ failure to speak out against Gosar, a Trump loyalist, Sununu added: “When a congressman says those things, of course they have to be censured … We’re talking about kicking people off committees because they don’t like one vote or the other? Again, I just think they have their priorities screwed up.”

Sununu is among a small number of senior, elected Republicans with the confidence to begin pushing back (although not directly) against Trump’s domination of the party.

Glenn Youngkin won a surprise victory earlier this month in Virginia’s governor’s race after a campaign during which he deliberately kept Trump at arm’s length, yet did tacitly echo the former president’s talking points. Some saw his win as a new Republican playbook for navigating future elections minus the specter of Trump.

Meanwhile, Chris Christie, a former governor of New Jersey and one-time Trump adviser, has told party members they needed to “renounce the conspiracy theories and truth deniers, the ones who know better and the ones who are just plain nuts”. Trump, who is considering another presidential run in 2024, attacked Christie while attempting to seek credit for Youngkin’s victory.

Friction has also been reported in Trump’s relationship with his protege Ron DeSantis, the Florida governor touted in Republican circles as the former president’s heir apparent and tipped for a likely 2024 White House run of his own. Trump is increasingly irritated by DeSantis’ soaring popularity, according to CNN, and has become “obsessed” with receiving credit for his rise.

A report in the Atlantic published on Sunday suggested that Trump’s once iron-clad grip on the Republican party might finally be slipping, arguing that the recent series of developments “point to the early stirrings of a Republican party in which Trump is sidelined”.

However, Trump continues to raise millions of dollars for an as yet undeclared presidential candidacy, and sends out regular endorsements of state and national candidates he believes embody the principles of Trumpism.

Until recently, Sununu was believed to be among them, but he reportedly upset Republican colleagues earlier this month with his announcement that he was not interested in pursuing a seat in the US Senate.

According to Politico, both the Senate minority leader, Mitch McConnell, and Rick Scott, chair of the National Republican Senatorial Committee, considered him as the perfect candidate to help wrest chamber control from Democratic hands in the 2022 midterm elections, but were blindsided by his decision.

“You just get so much more done as governor,” Sununu told CNN on Sunday. “Governors are the ones that have to implement and design programs, create opportunities, and we as governors have the best opportunity to offset some of the negative things coming out of Washington. The Senate and House really don’t have any power to do that.”