Former Acting FBI Director Andrew McCabe told "CBS This Morning" on Friday he "wouldn't dismiss Mr. [Michael] Cohen as a witness" despite his credibility problems. In explosive testimony earlier this week before the House Oversight Committee, Cohen accused President Trump of committing several crimes and called him a "racist" and a "conman." Cohen, the president's former personal attorney, is already heading to prison for lying to Congress

"The thing I found fascinating by Michael Cohen's statements was the amount of exactly that sort of corroborating information that he referred to and maybe revealed in his testimony. So there is a lot – there's a lot there. I wouldn't dismiss Mr. Cohen as a witness who would be, you know, unhelpful to any sort of prosecutorial efforts simply by virtue of his guilty plea in his case," McCabe said.

Democrats are expanding their investigation of potential criminal conduct by the president, saying Cohen laid out a "road map of criminality committed by the president."

McCabe also addressed other headlines this week, including a startling New York Times report that suggests President Trump ignored advice from key advisers and insisted on granting Jared Kushner a top-secret security clearance.

Though McCabe made clear his knowledge of the situation is limited to The Times' reporting, he offered his perspective as someone who has been involved in high-level security clearance matters for many years.

"The mere fact that the president has the authority to act in this way doesn't necessarily make it a good idea. There is a very detailed, thoughtful, careful process in place to ensure that security clearances are only given to people under optimal circumstances. When that process results in a negative recommendation, that is something that I have always seen administrations adhere to," McCabe said.

President Trump has repeatedly attacked the credibility of the FBI, its leaders and referred to investigations as baseless "witch hunts." According to a report from the Wall Street Journal earlier this week, the bureau has been forced to aggressively recruit candidates, something it has rarely ever done. McCabe said the president's comments about the organization have had an "undeniable" effect on recruitment.

In his new book, "The Threat: How the FBI Protects America in the Age of Terror and Trump," McCabe writes, "The president exposes himself as a deliberate liar, someone who will say whatever he pleases to get whatever he wishes. If he were on the box at Quantico" — meaning an FBI lie detector — "he would break the machine." Part of what McCabe identifies as Mr. Trump's threat is his lack of candor and his hostility towards the bureau.

"I think that the president's relentless attacks on the FBI and on the intelligence community at large make the job of protecting this country and keeping our citizens safe harder every day," he said. "It is dispiriting. I think it erodes their ability to get in the game and do the job every day, and it erodes public confidence in the work that they do which is not helpful."

It's still unclear whether special counsel Robert Mueller's final report on Russian meddling in U.S. elections and possible coordination between the Trump campaign will be released to the public, but Deputy Attorney General Rod Rosenstein, who oversees the special counsel, said earlier this week "there are a lot of reasons not to be transparent about what we do in government."

"I think Rod was referring to the longtime DOJ policy or practice of not sharing facts and circumstances of cases that are not charged and that certainly is the precedent and the tradition. But as we know, we have a Justice Department that has many examples of departing from precedent, tradition in the recent past. I think that the incredibly extensive sharing of not just report conclusions but FBI underlying investigative materials in the Hillary Clinton case, sharing at an unprecedented rate with the Hill, those are decisions made by the Department of Justice and I think they'll have a tough time reconciling that act with the deputy attorney general's statements."