Lanny Davis, the former lawyer for Michael Cohen who now serves as his advisor, still has a lot to say about his client's good intentions.

"[Cohen] will, I hope, have an opportunity to tell his personal story about what he did for Donald Trump, how ashamed of that activity he now is," Davis told WGBH News’ Joe Mathieu on Thursday.

Davis said he also hopes Cohen has the chance to explain to the public "what caused him to change" when he decided to plead guilty to lying to Congress in November.

"The quick answer [to what changed his mind] is what he saw as very troubling personal character flaws, to say the least, in the man that he worked for as a lawyer in the private sector, became positively frightening," Davis said.

In a wide-ranging interview three weeks after Cohen was sentenced to three years in prison for those lies and financial crimes he committed while working for Trump, Davis said he does not think that Cohen's testimony will be the "smoking gun that brings down Donald Trump." He doesn't think such a weapon exists.

Cohen, who in November pleaded guilty to lying to members of Congress about President Trump's knowledge of a proposed real estate project in Moscow, is just one factor in the investigation into the president, Davis said.

He also said he does not support Democratic Party-led impeachment of the president, and that the better move would be to wait for "the removal of Donald Trump with a bipartisan Congress or his defeat in 2020."

"That is the best alternative, unless Republicans rise above their own personal, political interest, which I do not disrespect, and look at the national interest in a president who respects the constitution, our alliances [and] democracy," Davis said.

Read more: Michael Cohen On Trump: 'The Man Doesn't Tell The Truth'

Davis called Trump "a danger to the country ... because of his abuse of the constitution."

"That is the standard for impeachment and removal," he said. "But I don't favor doing anything as a one-party vote. That will harm the Democratic Party, and it will certainly harm our constitution, because ... the removal of the head of the country, the president of the United States, would be for partisan reasons and not for the very grave reasons of abusing the constitution."

Davis said that if Trump either doesn't run in 2020 or loses re-election, the Democratic Party will need to do a lot to repair the damage done to the country by partisan polarization.

"There will be a lot of work to do to explain to Trump voters why it was necessary to remove him, or why his support collapsed and he decided not to run again," Davis said. "There will be anger towards what are viewed as the elites who are anti-Trump."

Davis, who served as the special counsel to former President Bill Clinton from 1996 to 1998, also took time to reminisce about a comment from Kenneth Starr, the independent counsel who investigated Clinton's scandal with White House intern Monica Lewinsky. The two once appeared in front of a class together, he said, and Starr's reflection on the Lewinsky case resonated with him.

"One question asked of [Starr] is, 'What would you have done differently?' ... He said, 'I wouldn't have accepted the assignment on Lewinsky.' And then I said ... 'Had Mr. Starr turned that assignment down, he would be now Mr. Justice Starr,'" Davis said. "Because he was a likely Supreme Court nominee under any Republican president. Because of the Lewinsky matter, and what I thought was poor judgment shown during that matter, he's never been able to be considered."

The lawyer even had a tidbit to throw in about Supreme Court Justice Brett Kavanaugh.

"There were several prosecutors on Ken Starr's team that served as leakers. I know with 100 percent certainty that Mr. Kavanaugh, and now Justice Kavanaugh, was one of them," Davis said. "Then Charles Barkley became the official spokesman and did most of the leaking."

Davis said that Trump's presidency has changed what, for him, has always been the "thrill" with which he regarded what the White House represents.

"Every time I drive by the White House, every time that I know that Donald Trump is in there, no other president gave me a sensation of fright," Davis said. "Fear. 'What might he do?'"