Bud Selig talks to Pedro Gomez about how difficult the steroid era was and the measures baseball took to combat it. (1:12)

NATIONAL HARBOR, Md. - The class was held just last week in Professor Bud Selig's classroom at the University of Wisconsin. The topic of the day, in the professor's "Baseball in American Society" curriculum, was a whopper: steroids and baseball.

Oh, if only there had been a camera rolling in that classroom that day. It was not Professor Selig's most comfortable lecture of the school year. He's the first to admit that.

His students weren't easy on him, baseball's commissioner emeritus said Monday, the day after learning he'd been elected to his sport's Hall of Fame. In fact, they kept raising their hands to grill him at every turn.

"Did they ever," Selig told ESPN, in a candid conversation on one of his least favorite subjects. "They were tough."

And the toughest question they asked, he said, was one that millions of baseball fans have wondered about for nearly two decades, one that hung over the celebration of Selig's election to Cooperstown this week.

"They asked me, 'When were you aware of it?'" Selig recalled Monday, "and, 'Why didn't you do more?'"

After students in his "Baseball in American Society" class at Wisconsin grilled Bud Selig on steroids, the commissioner emeritus and newly elected Hall of Famer was forced to face his legacy. Ron Edmonds-Pool/Getty Images

Amid all the change and all the growth and all the innovations that propelled this former commissioner into the Hall of Fame, it is still that question about that era that never seems to stop lurking in the shadows. So how does Selig answer it? Here's how:

In 1998, he said, he went to St. Louis to watch the Cardinals play the Cubs, as Mark McGwire dueled Sammy Sosa for what was then baseball's most beloved record -- Roger Maris' 61 homers, which for 27 years had stood as the single-season home run mark.

"I talked to the Cubs about Sammy," Selig recalled. "The Cardinals were thrilled with McGwire. It was a big civic celebration."

And no one on either team mentioned a word, he said, about what was really driving those two men toward the threshold of history. So Selig said he turned to his "baseball people" in the commissioner's office.

He says he asked, "What's causing this?" And they reeled off what we would now describe as the usual, everything-but-the-elephant-in-the-room, theories: Expansion. The dilution of pitching. Questions about whether there was something different about the baseball.

"They gave me a whole bunch of reasons," Selig said. "And I kept asking about steroids."

He said he then went to see one of his favorite Milwaukee Brewers, the recently retired Robin Yount, and asked him the same question: What about steroids?

"And he said, 'Commissioner, the only guy I knew [who was taking them] was [Jose] Canseco,'" Selig said. "But he said, 'I don't know what's going on now.'

"And I talked to a lot of baseball people," Selig went on, "over and over and over again. But you know, by 2000, I moved (to impose testing and suspensions) in the minor leagues, which I could do unilaterally. So that's 15 years ago. So this idea that we didn't do anything just isn't accurate.

"Now let me ask you a question. And I'm being serious. If you had been me then, what would you have done?"

"You know, I've thought about it a hundred times, because I'm pretty tough on myself," Selig said, finally. "And I honestly don't know what else I could have done. That's my answer."

But that wasn't his final answer. He also wanted to make it clear that once everyone in his office was ready to admit they had a huge problem on their hands, it was the players' association that stood squarely in the way.

He told tales of raging fights at the bargaining table that went on for hours. And as he heaped blame on the players' association, he vented his frustration in a way he had never vented it before.

"I never understood," Selig said. "Why would you defend a bunch of cheaters?"

And that is how Professor Selig laid out this controversial saga to his students last week, how he remembers those times to this day. He firmly believes he did what he could.

"I went back through the whole negotiations," Selig said he told his class. "I went through everything. And I told them, 'There was nothing I could do. It's collectively bargained.'"

But was it really that simple? Is it ever that simple? Clearly, Bud Selig wrestles with those doubts to this day, because after giving his side of this story for 11 minutes, he then turned to me.

"Now let me ask you a question," he said. "And I'm being serious. If you had been me then, what would you have done?"

Frankly, I was amazed that he asked. But I also had no trouble admitting to the commissioner emeritus that I thought back on those times a lot. And like a lot of members of the media, I carry a deep sense of guilt about that era and the way it was covered. I told him I wish I'd done more. I wish I'd asked more questions. I wish I'd learned more. I wished I'd said and written more.

So that, I told him, was what I thought he could have done. He was the commissioner. So the one thing he could have done, without needing a bargaining table to do it, was raise this issue, speak about it more, admit to it earlier and bring it to the forefront.

"That's fair," Selig replied. "That's very fair."

A moment later, he looked me right in the eye again. "Maybe you're right," he said. "Maybe I should have said more."

It is now many, many years later, of course. Eighteen years since McGwire and Sosa. Way too late to jump in a time machine and go back to those days when so much more could have, and should have, been done and said.

Selig constantly tells himself that, ultimately, baseball dealt with the problem. It took too long. But in the end, he said, baseball "wound up with not just the toughest testing in sports, but in America."

"But did it come with a lot of pain?" Selig asked, rhetorically. "You bet it did."

And this was the true measure of just how much pain. Even on one of the greatest days of his life in baseball, that pain was impossible to dismiss, just as these questions are impossible to dismiss. Even in a college classroom in Madison, Wisconsin.