Sen. Mitt Romney, R-Utah, said on Sunday that President Donald Trump "could substantially improve his game" in helping shape the nation's character.

In a wide-ranging interview with CNN, Romney also discussed the possibility of Trump's impeachment, his decision to vote against a judicial nominee who called President Barack Obama an "un-American imposter," and voiced his displeasure with a controversial Alabama abortion law signed last week, among other topics.

Romney, who was openly critical of Trump during the 2016 campaign and has occasionally voiced displeasure with him since, said Trump "could substantially improve his game when it comes to helping shape the character of the country."

"I think young people, as well as people around the world, look at the president of the United States and say, 'Does he exhibit the kind of qualities that we would want to emulate? And those are qualities of humility, of honesty, integrity?'" Romney said. "And those are things where I think there's been some call where the president has distanced himself from some of the best qualities of the human character."

Romney was asked about Rep. Justin Amash, R-Mich., who said Saturday that Trump engaged in "impeachable conduct," a conclusion he reached after reading the entirety of special counsel Robert Mueller's 400-plus page redacted report. Romney said Amash "reached a different conclusion than I have," adding however that Amash made "a courageous statement.”

Amash was the first Republican member of Congress to say Trump's conduct is impeachable. But Romney said he does not believe most Americans are in favor of impeaching Trump.

"And I think those that are considering impeachment have to look also at the jury, which would be the Senate," Romney said. "The Senate is certainly not there either."

"As I read the report, I was troubled by it. It was very disappointing, for a number of reasons," he added. "But it did not suggest to me that this was time to call for impeachment ... I don't think impeachment is the right way to go."

Asked about Alabama's recently signed abortion bill that would outlaw virtually all abortions in the state, Romney said he did not support it.

Now the nation's most restrictive abortion law, the legislation even outlaws abortions that are the product of rape or incest, only allowing for cases when a woman's life is in jeopardy.

"I believe that there ought to be exceptions," Romney said. "I'm pro-life, but there ought to be exceptions for rape and incest and where the life of the mother is at risk. But, look, you're seeing laws on both sides of this argument that are in the extreme. And whether it's New York and Virginia, or whether it's Alabama and Missouri, people have gone to the wings, if you will. I don't think that's productive. I think something much more towards the center makes a lot more sense."

Romney also explained why he voted against Michel Truncale, a Trump pick for the federal bench in Texas who was confirmed last week. Truncale called Obama an "un-American imposter" and lambasted liberals.

"No, it's actually a very personal thing for me, which is, I ran against President Obama," Romney, the 2012 GOP nominee, said. "I disagreed with him on a whole host of issues. We went after each other very aggressively. But I completely rejected the whole idea that he was not born in the United States, that he was un-American in some way, that he was an impostor in that respect."

"And so, when a judge came forward making that kind of claim in his past, that was just not something I could subscribe to," he continued. "So, it wasn't a matter of his politics or right-wing, left-wing. ... As a matter of fact, during my campaign, when there was an instance when someone said that President Obama was un-American, I insisted they apologize for that and retract that statement. So, in a setting like this, I had no choice but to say, look, I do not subscribe to this un-American charge against President Obama."