ANY GOOD ARTIST has a critic in his head. Jack Ohman, who won a Pulitzer Prize on Monday, has at least two.

In 2013, Ohman inherited the chair of his longtime friend Rex Babin, who died a year earlier of cancer. Babin had been the Sacramento Bee’s editorial cartoonist for more than a dozen years, while Ohman was the cartoonist for the Oregonian in Portland. The men had met in their mid-20s, and over the next quarter-century, Babin was forever critiquing their fellow cartoonists’ work and pushing them to do better.

“Rex was always like, ‘You’ve gotta draw in perspective!’ And he’d say, ‘He totally phoned it in on that building,’ ” recounts Ohman, before framing that symptom more widely: “I think there’s a lot of phoning it in, in our culture.”

Ohman has been at the Bee for three years now, in his friend’s former seat. “It’s very poignant to work there,” says Ohman, who celebrated with Babin’s widow Monday after news of his Pulitzer win came. And Ohman notes that Babin’s lingering critiques influenced his winning portfolio. He hears his friend still. “It’s a good voice to have in your head.”

Then there’s the critiquing voice consistently outside his head. That is the sound of Dan Morain, his editor at The Bee. Morain’s role was especially crucial concerning a cartoon in the Pulitzer portfolio that comments on the Supreme Court’s same-sex marriage ruling last year.

“He sent me back to the drawing board on the Supreme Court cartoon,” Ohman recounts. “He said: ‘I like this, but you can do better.’

“So you go back [to the board] at 1 o’clock. And he was right: I could do better.”

Ohman notes that he honed not only his idea, but also his artwork — the twin voices of Babin and Morain urging him on. “I really futzed over that building and that projection.’

And then, once that day’s cartoon goes out into the world, Ohman naturally faces another round of scrutiny.

“This is a sophisticated readership” in California’s capital, he says. “Here, you can’t just run dumb jokes by them. I’m always waiting to be critiqued by someone, from [Gov.] Jerry Brown on down.”

Ohman’s winning portfolio also reflects his ability to find just the right tone for the topic. Particularly challenging can be the handling of breaking-news tragedies.

“Those are the kind of cartoons that test a cartoonist,” says Ohman, who was a Pulitzer finalist in 2012 while working in Portland. “The default mode is to be funny and clever. With so many tragic incidents in the past year, it tests the tensile strength of everything you’ve got in your quiver. I’ve prided myself on having a flexible style and being able to do one kind of cartooning one day, and another style another day.”

Another cartoon in his winning portfolio, in the wake of news about last year’s Charleston church shooting, required Ohman to use quick precision. “Cartoonists hate doing simple cartoons, but I spent probably 25 minutes on the gun-and-the-[Confederate]-flag cartoon,” he says. “I’m writing-driven, but I’m also very careful about my artwork.”

No matter how many voices of critique swirl near his head, Ohman naturally has a strong self-belief.

“I have to live with my own work. That’s between me and me,” Ohman says. “I’m not complacent. I’m proud of what I do, and try not to sit back.”

He inherited Rex Babin’s chair, after all. It may be for resting, but it was not built with laurels.