Democratic presidential hopeful Tim Ryan said it's getting "harder and harder" to see why Democrats shouldn't impeach President Donald Trump after Special Counsel Robert Mueller's public remarks this week.

"I really don't want to impeach, but at this point, I don't know how we don't," the Ohio congressman told the Des Moines Register in an interview Friday night following a Des Moines house party where Ryan gave remarks and took questions from an audience of about two dozen.

Ryan had earlier resisted joining calls for Congress to move toward impeachment proceedings. He said Friday he was waiting to hear whether Mueller believed there was a criminal case to be prosecuted against Trump.

"The question I wanted him to answer for me was if Donald Trump was Tim Ryan or an auto worker in Youngstown or a farmer in Iowa, would you have prosecuted him?" Ryan said. "And I think (Wednesday) the answer to that was yes, he would have if he could have."

Mueller spoke publicly Wednesday for the first time about the two-year investigation he oversaw into Russian interference in the 2016 presidential election. Mueller's report concluded that while Trump and his campaign did not conspire with the Russians to influence the election, the campaign in some instances welcomed the foreign power's help.

More coverage from the Des Moines Register

On the question of whether Trump attempted to obstruct the investigation, Mueller said his office did not reach a conclusion because Justice Department guidelines prevent a sitting president from being indicted. But he was clear that the investigation did not exonerate Trump.

"If we had confidence that the president clearly did not commit a crime, we would have said so," Mueller said. "We did not, however, make a determination as to whether the president did commit a crime."

The public statement from Mueller, who stayed silent during the course of the investigation, led several prominent Democrats, including many presidential candidates, to call for Trump's impeachment.

While many Democrats have become more forceful about impeachment, House Speaker Nancy Pelosi has downplayed the possibility, saying the Senate would never vote to remove Trump from office. Ryan said it's Pelosi's decision how to approach the issue.

"She's got a very diverse caucus on her hands," he said. "We've got a lot of frontline members who, they have a different opinion. They don't want to go down this road."

Ryan said Friday that he doesn't relish the possibility of impeachment.

"I know what this is going to do," he said. "This is going to throw gasoline on all the big divisions in the country, and that sucks because we’re already so divided and we’re trying to pull the country back together."

But he noted that Congress has a constitutional duty to act.

"I feel a lot of it’s like disciplining your kid," Ryan said. "You don’t want to, right? You know? You don’t necessarily want to, but you do it because it has to be done and that’s part of being mature, and it’s getting harder and harder to see why we shouldn’t."

At a meet and greet in Carroll on May 20, Ryan told attendees, "I don't think there's any question that (Trump) obstructed justice on multiple occasions."

At that same event, he said Democrats should hold public, televised hearings to educate people on Trump's actions as detailed in Mueller's report.

"We've really got to bring people along to say, 'No, this isn't just a Democratic witch hunt,'" Ryan said.