WASHINGTON – Former White House attorney Ty Cobb defended special counsel Robert Mueller on Tuesday, calling him an "American hero" and disputing President Donald Trump's characterization of Mueller's investigation as a "witch hunt."

"I've known him for 30 years as a prosecutor and a friend and I think the world of Bob Mueller," Cobb told ABC News in a podcast interview. "He is a very deliberate guy, but he's also a class act and a very justice-oriented person."

Cobb – who left the White House legal team at the end of May 2018 – said he did not agree with the highly critical statements Trump and his attorney Rudy Giuliani have made about Mueller's investigation into Russian interference in the 2016 election.

He conceded that Trump and Giuliani have been effective in ratcheting up "the public's concerns about the investigation and its legitimacy" but he said, "It's not my view that it's a witch hunt."

"I object to that approach, but it's his choice," Cobb said of the president's criticisms of Mueller's work.

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He then heaped more praise on Mueller.

"I think Bob Mueller is an American hero," Cobb said. "I think Bob Mueller is a guy that, even though he came from an arguably privileged background, has a backbone of steel. He walked into a firefight in Vietnam to pull out one of his injured colleagues."

Cobb said he does not expect Mueller to uncover evidence of a conspiracy between the Trump campaign and Russians working to sway the election.

"But at the same time, what do I know?" he added, conceding that "it's conceivable" Mueller's final report could reveal something new.

He said that while Mueller's team has "done an effective job" of "laying out the facts as they develop" in various court filings, none of those detailed and extensive documents have directly linked Trump to Russian election meddling.

Cobb said that while he understands "the impetus" for people to wonder, "'Why does the president act guilty?'" it is important to remember that Trump has consistently cooperated with Mueller's team.

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"In reality, this is a president who did not fight the special counsel in terms of its evidentiary request," he said. "The president was very clear from day one that anybody who was asked to speak with the special counsel "should be encouraged to do so voluntarily."

Cobb said he believes congressional Democratic leaders, such as House Intelligence Committee Chairman Adam Schiff, D-Calif., share his belief that Mueller's probe will not uncover evidence of collusion. He said that is why they are expanding their investigations into Trump's associates and finances.

"Schiff has tacked to basically saying Mueller didn't look into enough things, and we need to be fishing around to find other possible avenues through which to get to the president," he said.

He said Schiff, along with House Oversight and Reform Committee Chairman Elijah Cummings, D-Md., and House Judiciary Committee Chairman Jerry Nadler, D-N.Y., are "hell-bent on issuing a lot of subpoenas to get to the administration and perpetuate this investigation."

House Minority Leader Kevin McCarthy, R-Calif., has expressed a similar view of the widening investigations by House Democrats.

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Cobb said that while he was working in the White House he was largely "able to prevent the president from going on the attack as to Mueller."

He said it was after "Rudy joined the team that the onslaught" against Mueller began.

"I think the president felt unleashed," Cobb said. "He's found this very frustrating. It's particularly frustrated him in foreign affairs. He doesn't like the timing. He wants this over, but its never going to be over. This will go through 2020, and if the president's re-elected it will go beyond that."

In the interview, Cobb also described the "chaos" of working in the Trump White House, beginning with his first day on the job, which he said was the same day that John Kelly replaced Reince Priebus as White House chief of staff and Anthony Scaramucci's brief stint as communications director came to an end.

"And it really never let up after that," Cobb said. "It was a challenging environment and it's not for everybody."

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Opposing view:Full release of Mueller report isn’t in the public interest