CBS White House correspondent Major Garrett on Wednesday said House Democrats were not exhibiting a "minimum standard of fairness" with their failure to question a law school professor summoned by Republicans for the impeachment hearings.

"It's worth pointing out that as the public watches what just happened they would say, ‘Wait a minute, there was another constitutional scholar there also who disagrees, but never got a question,'" Garrett said on CBS's Special Report.

Democrats should be asking the scholar, George Washington University's Jonathan Turley, about his opposition to impeachment so there could be a "competing set of opinions," Garrett said.

"The Democrats' reluctance to even bring that into the conversation—I know Trump supporters will say, ‘See, they're not even interested in an opposing point of view. They want a singular, repetitive accusation against the president, that everything has been proven, and it's all impeachable,'" he continued.

"I think for Trump supporters, they will look at it and say, ‘that doesn't seem fair,' and it reinforces the president's argument, whether you think his conduct was proper or improper, that this is not being done on a basis that achieves a modicum or a minimum standard of fairness," Garrett said.

Turley, who was summoned by Republicans, testified that he was "concerned about lowering impeachment standards to fit a paucity of evidence and abundance of anger."

"So we’re all mad, and where has it taken us? Will a slipshod impeachment make us less mad? Will it only give an invitation for the madness to follow in every future administration?" he asked. "This is not how you impeach an American president."

The three other constitutional scholars summoned by Democrats called for Trump to be impeached. Michael Gerhardt, who teaches at the University of North Carolina School of Law, said, "I just want to stress that if what we're talking about is not impeachable, then nothing is impeachable."