Former Watergate prosecutor Jill Wine-Banks explained to MSNBC's Ali Velshi that the major thing is that this testimony will be public. Up until now, everything Cohen has divulged has been hidden from American view.
"It's time for the public to have the education about what the facts are and so now that he's cooperating and willing, to tell the truth, they can hear the truth from him," said Wine-Banks.
Americans can finally "judge his credibility themselves. So, the fact that they are doing it now in public is a really important educational tool," she said.
There are other questions that Cohen can clear up for Americans searching for confirmation on the Mueller investigation.
First, Wine-Banks said that Cohen can once and for all clarify that "Individual Number One" is in fact, Donald Trump.
"He also had a relationship with Donald Jr. and he may be able to give evidence about that," Wine-Banks said. "He may be able to give evidence about payoffs beyond Stormy Daniels and Karen McDougal and maybe even payments to other women but also to things that are more related to the real estate business and the fact that he's coming in voluntarily is also important."
The Trump Tower meeting with Russian lawyer Natalya Veselnitskaya is another thing he might have some insight into.
Cohen "can show evidence that there is a reason why sanctions are being dropped and that there is a quid pro quo," she continued.
She noted that many in the public, indeed many Republican officials, have given Trump a pass because much of this information has not been given past the grand jury.
"They didn't want to hear the truth in the past, they wouldn't issue subpoenas to a lot of other witnesses," she said of House Republicans, who closed the investigation nearly one year ago.
"Obviously there's now enough corroboration that he's telling the truth that the prosecutors are willing to accept his cooperation," Wine-Banks explained. "So, I think that that also tells us something about why we could believe what he's saying now. I also want to know about any trip he took to [to Prague.] There was some convincing evidence that he actually did go to Prague and I would like to hear more about that."
If he did go to Prague it will be a clear link to the Russians and interference in the election.
Watch her full take below:
