More than two decades ago, in the aftermath of a bruising campaign for Congress, Mike Pence did what few aspiring politicians would contemplate.

He penned a reflective mea culpa.

Titled “Confessions of a Negative Campaigner,” Pence’s article opened with a passage from the Bible about sinners. He admitted that as part of a failed bid for Congress in 1990, he’d waged “one of the most divisive and negative campaigns in Indiana’s modern congressional history.”

For that, Pence said, he was sorry.

Then he laid out a vision for what a campaign should be, including this: “First, a campaign ought to demonstrate the basic human decency of the candidate. That means your First Amendment rights end at the tip of your opponent’s nose — even in the matter of political rhetoric.”

Old friends of the governor, especially those who recall that moment of shouldering responsibility, candidly admit to having been taken aback by recent speculation that Pence will partner with presumed GOP nominee Donald Trump.

On one hand, there’s the self-confessed opponent of negative campaigning.

Then there’s the vitriolic, name-calling Trump.

“It’s black and white, it’s night and day,” said Bill Styring, a retired economist with a long history in Republican establishment politics, of Trump’s possible selection of Pence as a running mate.

Styring was research director for the Indiana Policy Review think tank when Pence was its foundation president. Pence invited Styring to join the organization in 1992, not long after he wrote that article for the review.

Styring and others who remember those words say Pence’s conversion into to a gentlemanly campaigner has been genuine and long-lasting.

They’re convinced that he deeply regretted the attack ads he ran against Democratic rival Phil Sharp. One especially controversial ad featured a man dressed ominously as an oil sheik, thanking Sharp for being the Arabs’ best friend.

“I remember the oil sheik TV commercial,” Styring said. “I don’t think Mike has ever forgiven himself for that.”

Pence has hinted so much. In a 2006 interview with The New York Times, he disclosed regret for becoming negative in that election after feeling attacked by his opponent. The decision, he said, violated his deeply held Christian faith.

“What was most painful to me was the bile in my throat over how I had responded,” he was quoted as saying. “My faith says, if someone strikes you on the cheek, turn the other. My response, after being attacked by my opponent, was to empty the silos on this guy.”

Styring remains an admirer of Pence, calling him one the kindest men he knows.

“Mike Pence would not be a very good attack dog,” he said.

It’s an assessment shared by others in recent days, especially in light of some others on Trump’s VP short list who seem happy to play the role.

Last Wednesday, as Pence cordially batted away reporters’ questions about the Trump ticket, former House Speaker Newt Gingrich appeared on an Ohio stage with the real estate developer, in full attack mode.

Gingrich’s target was presumptive Democratic nominee Hillary Clinton. Covering the event, the Washington Post described him as Trump’s alter ego — “a combative and septuagenarian politician who naturally aligns with anti-establishment fervor and eschews message discipline.”

That’s so not Mike Pence, said longtime friend and mentor, Muncie lawyer Van Smith.

“Mike is the epitome of good taste,” Smith said.

Such words are echoed by other friends of the governor, including David McIntosh, a former congressman who is now head of the Club for Growth in Washington, D.C., which has openly feuded with Trump.

McIntosh said Pence — a polite but unerring, disciplined conservative — later distinguished himself during six terms in Congress by elevating cordiality with political opponents.

“There’s a huge contrast in style,” he said of Trump and Pence. “Mike is a civil politician and a statesman.”

McIntosh, too, is trying to make sense of a potential Trump-Pence partnership.

Though he hadn’t talked to the governor about it, McIntosh said he thinks Pence may have seen an inquiry from Trump as a call to duty in troubled times.

“I know him well enough to know how he thinks, that if this is something I can do for my country, I’m willing to serve,” he said.

Maureen Hayden is statehouse bureau chief for CNHI newspapers.