Rosenblum: Persistent, opinionated caller to the Minneapolis Star Tribune is greatly missed.

Duane Markus played second base for a Chicago Cubs farm team back in the 1960s.

He was a beloved middle-school social studies teacher, the proud father of three grown sons, a CEO who made sandwiches for his employees every Friday.

Everybody called him "Dewey."

I knew none of that until this week.

The Duane Markus I knew was a die-hard Star Tribune subscriber who liked to push my buttons. With the predictability of a Swiss train, Markus' hand reached for his phone at odd hours — just after he'd read what, in his view, was my latest left-of-center social issues column, diplomatically speaking.

Many mornings, Markus greeted me before my colleagues did.

"Gail, this is Duane Markus."

"You're my favorite liberal," he'd tell me.

Then Mr. Markus would begin a multi-minute discourse, polite and calm, never a screed, but delivered with an audibly hopeful tone of setting me straight.

He always left his phone number.

Markus was surprised the first time I called him back. We had an awkward and brief exchange. I think I unearthed something earnest like, "Thanks for taking the time to share your opinions," or "We really value our loyal readers."

I think he said something like, "Thanks for calling me back. I never expected it."

Sometimes when I heard his voice, I'd push delete. I was on a deadline, or I just wasn't feeling up to another debate.

I'm really regretting that now.

Markus died on July 2, at age 73. I didn't know he was battling cancer, or that he'd struggled with multiple health issues, from a kidney he lost playing baseball to heart attacks in later years.

I do know that when I came across his obituary, I felt shock and sadness. Nothing near the loss felt by Ann, 67, his wife of 39 years, or his three sons — Chad, 46, Andy, 36, and Jeff, 34 — or their wives or two grandsons, but a genuine sense of loss nonetheless.

Markus taught me that two people with starkly different views on how this planet should operate can have refreshing and respectful conversations. Sometimes, those conversations end with, "I'll give you that."

"Constantly, constantly," said Ann, a Realtor. "Every time there was an article slanted liberal, he'd call the newspaper. Sometimes I'd say, 'Duane, stop doing that. They might stop selling us a subscription.' "

(Trust me. No danger of that.)

Son Andy, who talked on the phone with his dad five or six times a week, laughed in amusement at his father's hobby.

"He was not afraid to pick up the phone," Andy said. "He would call the Star Tribune, state senators, the House of Representatives. Yeah. He would pick up the phone."

Andy said his "one-of-a-kind" father didn't have a problem with state and federal government having a welfare system.

Not surprisingly, Markus didn't want a funeral. He didn't want to be dressed in a suit.

He wanted a party with nice drinks, where his family and friends could tell "Dewey stories."

That party was held July 14 at the Wayzata Country Club. About 250 people attended.

Family members, friends and former students toasted the memory of a 5-foot-7 Minneapolis kid who played football, hockey and baseball at Central High School, then became captain of the University of Minnesota's championship baseball team before being signed by the Cubs organization.

A guy who preached that knowledge is power, and who mentored countless young people. Who liked to say "Keep dialing for dollars, kid!"

A man whose favorite spot on Earth was his 85-acre farm, surrounded by his family.

And, I'm guessing, close to a phone.

He was persistent and opinionated.

I'm really going to miss him.