WATCH: Ex-GOP staffer goes down in flames on CNN for dismissing Mueller testimony as 'theater'

On Tuesday's edition of CNN's "Anderson Cooper 360," former Republican National Committee Chief of Staff Mike Shields derisively waved away former special counsel Robert Mueller's upcoming testimony before the House Intelligence and Judiciary Committees as inconsequential and unimportant — and was immediately challenged by chief political analyst Gloria Borger.

"Look, this entire thing is theater," said Shields. "All the fundraising emails are already written and ready to go out tomorrow from all the new superstars on that committee that are going to get their five minutes. Jackie Speier said that she had a fantasy that Robert Mueller is just going to read the report."

"I mean this is — I keep waiting to hear Sonny and Cher, because this is Groundhog Day," said Shields. "This is just the same story over and over again. Robert Mueller will come up, the country is going to go 'whatever,' and Democrats have blown their chance to have an agenda."

"But most of the country hasn't read the Mueller report," pointed out Borger.

"They won't read it tomorrow, either," said Shields.

"They may have it read to them and may see it coming from a credible witness, Robert Mueller," said Borger. "There may be some questions ... he can answer. For example, did you — was the president a cooperative witness here?"

"Or is how the president characterized the report accurate?" cut in fellow contributor Kirsten Powers.

"Right, or how [Attorney General William] Barr characterized it," agreed Borger.

"I love that Democrats want to do this," sneered Shields. "I love that they think that they're going to get something out of it. They're taking a round peg and they're asking Robert Mueller to slam it in this square hole that the public doesn't care about anymore."

"Not necessarily," said Borger. "Not necessarily."

Watch below: