Spurning debate offers, Geoff Diehl only agreed to forums on conservative radio. His campaign says that’s his strategy.

GOP gubernatorial candidate Geoff Diehl.Barry Chin/Globe Staff

As he vies to be Massachusetts’ GOP gubernatorial nominee, Geoff Diehl refused to face his primary opponent, Chris Doughty, at a TV debate proposed by WCVB, WBUR, and the Globe. He reportedly declined a debate invitation on NECN, the regional cable news channel. And he rejected an offer to appear on GBH, prompting the public station to instead run a year-old interview with him.

“A first for us,” host Jim Braude said of Diehl’s debate declination, “with either party.”

Diehl instead has made what his campaign cast as a strategic decision: He committed to two debates — both on the conservative talk radio network WRKO and each hosted by a longtime Diehl supporter in Howie Carr and Jeff Kuhner.

The candidates ultimately squared off in just one, held nearly seven weeks ahead of the Sept. 6 primary on Carr’s show in what was the first, and most likely last, forum featuring the two candidates.

The relative dearth of primetime faceoffs has weaved itself into the fabric of the primary, with Doughty for months needling the Donald Trump-backed Diehl to debate him, and Diehl, comfortably ahead in public polling, regularly dismissing him.

But it also pointed to a wider dynamic rooting itself in some Republican circles. Diehl has built his campaign on a stark appeal to the GOP’s more conservative base, seeking support of national Republican figures and falsely calling the 2020 election “rigged.” He easily won the backing of a state party at a convention that showcased its own shift to the right.

Calculating there is little to gain in engaging with major news outlets, Diehl stuck to the red — and, in Massachusetts, the relatively thin — waters of conservative media, where his campaign argues he can best reach those most likely to vote in a primary where unenrolled voters, too, could cast a ballot.

“It’s a Republican primary and the candidates should be speaking to a Republican primary audience,” said Amanda Orlando, Diehl’s campaign manager. “Jim Braude doesn’t have that.”

Critics, however, contend Diehl is walling himself off from potentially unfriendly questioning. Hours after WBUR reported that Diehl had rejected the invite from the three-outlet consortium, Diehl said he also declined to appear for an interview with the Globe’s editorial board before it makes it an endorsement in the race.

Diehl called the process a “charade” and the Globe “one of the most liberal newspapers in the nation,” arguing it would be a waste of his time to appear.

“Republican primary voters don’t turn to the Globe for news about Republican politics because they know the newspaper isn’t open-minded enough to print fair and unbiased reporting,” Diehl said.

Doughty, who’s vacillated between framing himself as a conservative and moderate Republican, appeared earlier this week before the board, his campaign said. Volunteers for his campaign also recently picketed outside a Diehl fund-raiser with signs that said: “Doughty agrees to debate 9 times. Diehl hides in basement like Biden.”

“It’s more than just debates. It’s any kind of press that’s not friendly — or press that he deems not friendly,” Doughty said of Diehl.

Doughty, a first-time candidate, said with no competitive Democratic primary for governor — Attorney General Maura Healey is the presumptive nominee — Republicans entered the summer with an opportunity to capture the electorate’s attention with a string of high-profile forums. That’s been lost, he argued.

“It’s a sad moment for Republicans,” the Wrentham Republican said. “Independents are the largest group of voters in our state. You need them, no matter what party that you’re in. And you have to do all media.”

Diehl’s campaign says that he has. Orlando said he’s done more than 300 campaign stops, and more than 100 media interviews since entering the field last summer. On Wednesday, he had scheduled stops in Chicopee and Springfield, and an interview with a local newspaper reporter in Greenfield.

Republicans elsewhere have been overt in shunning the press. In Florida, the state Republican party fully barred many outlets from covering a major party gathering, but allowed in conservative outlets. Later, Florida Governor Ron DeSantis’ spokeswoman tweeted that “my message to them is to try crying about it.”

In Georgia, US Senate nominee Herschel Walker has regularly retreated into events that bar the press from attending. GOP gubernatorial candidates from Ohio to Nevada to Nebraska have also avoided the debate stage, the Associated Press reported.

Individuals have a tendency to interact selectively with media outlets they perceive to echo their own views, said Costas Panagopoulos, the chairman of Northeastern University’s political science department.

This happens with candidates on both ends of the political spectrum, he said, but is pronounced on the right because of the perception that mainstream media has more liberal perspectives.

“That may be more myth than reality,” he said, but is a national theme nonetheless. “Not only is this pattern more broad, but it’s been happening for a very long time. There are highly visible personalities that have endeavored to cement that viewpoint for their own gain. I am thinking mainly here of Donald Trump, but he isn’t the first person to criticize the mainstream media. [Richard] Nixon and other presidents often did the same thing.”

To be sure, avoiding the debate podium is also not a new phenomenon in Massachusetts GOP primaries. During his 2018 run for US Senate, Diehl appeared in a lone Boston Herald radio debate with his opponents, John Kingston and Beth Lindstrom — the latter of whom regularly appeared at forums where she was the only candidate.

The same year, Governor Charlie Baker did not debate his primary opponent, Scott Lively, a divisive pastor who once said he was “opposed to the gay agenda” and wrote a book alleging the Nazi party was controlled by gay men who hid their sexual orientation.

But when he sought the open governor’s office in 2014, Baker regularly squared off with his primary opponent, Mark Fisher, in debates hosted by WBUR, the Globe, and others.

Every other statewide candidate running in a competitive Democratic and Republican primary also agreed to appear in debates this year hosted by GBH or the WBUR/Globe/WCVB consortium, including Diehl’s running mate, Leah Allen.

Orlando said the WRKO hosts did not agree to host a lieutenant governor’s forum, meaning the campaign had to look “for other avenues” for Allen to debate Kate Campanale, Doughty’s running mate.

And should he win the primary? Orlando said Diehl would debate on a “variety” of networks against Healey, who has led him by yawning margins in public polling. After winning the Senate nomination in 2018, Diehl also agreed to three debates with Senator Elizabeth Warren.

In a general election, Orlando said, “the universe of voters is different.”

“He would be willing to do many debates,” she said.