Sen. Ron Johnson, R-Wis., said Sunday that the administration officials who provided the whistleblower with information on President Donald Trump's conduct toward Ukraine "exposed things that didn't need to be exposed."

Johnson was one of several Republicans to offer up varied defenses for the president on Sunday after a week that saw three officials at the heart of U.S.-Ukraine relations testify publicly in the impeachment probe. The three career diplomats who testified shed new light on the Trump administration's efforts to circumvent normal diplomatic channels to get Ukraine to investigate former Vice President Joe Biden and his son Hunter Biden.

Johnson, who spoke with the president about why military aid was being withheld from Ukraine before the administration released the hold in mid-September, said on NBC's "Meet the Press" that what he wanted "to point out is the damage being done to our country through this entire impeachment process."

"It's going to be very difficult for future presidents to have a very candid conversation with a world leader because now we've set the precedent of leaking transcripts," he said. "The weakening of executive privilege is not good. And by the way, these individuals that leaked this, if their interest was a stronger relationship with Ukraine, they did not accomplish this. Having this all come out into public has weakened that relationship and exposed things that didn't need to be exposed."

He pointed to a trip he took to Ukraine with Sen. Chris Murphy, D-Conn., to speak with Ukrainian President Volodymyr Zelenskiy in early September, saying that after the discussion he told Murphy "let's try to minimize" the hold on military aid.

"This would have been far better off if we would have just taken care of this behind the scenes," he said. "We have two branches of government. Most people, most people, want to support Ukraine that are trying to convince President Trump."

"If the whistleblower's goal is to improve our relationship with Ukraine, he utterly — or she — utterly failed," Johnson said of the CIA employee who, in an official complaint, said the president was soliciting help from a foreign nation in his 2020 reelection efforts. Their complaint set off a series of events that eventually led to the House's impeachment inquiry.

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That inquiry reached its most prominent point yet last week with the onset of public testimony, which featured the top U.S. diplomat in Ukraine, Bill Taylor, revealing that one of his staffers overheard a phone call on July 26 in which the aide heard Trump ask Gordon Sondland, the U.S. ambassador to the European Union, about "the investigations," meaning the probes into Democrats.

The staffer was later revealed to be David Holmes, the counselor for political affairs at the U.S. Embassy in Ukraine, who appeared for a closed-door testimony on Friday.

Holmes told impeachment investigators Friday that he heard Sondland tell Trump that Zelenskiy "loves your ass," to which Trump asked, "So, he's gonna do the investigation?" Sondland replied that Zelenskiy was "gonna do it," adding that the Ukrainian leader would do "anything you ask him to."

Holmes said he was able to hear the discussion because Sondland held the phone away from his ear because of how loudly Trump was speaking. But Holmes did not take notes of the call, telling lawmakers that he was relying on his clear recollection of the events, which he immediately told fellow embassy staffers about.

Sondland, who did not mention the call in either his initial October deposition and or in subsequent written testimony he gave this month, will appear publicly before impeachment investigators on Wednesday.

Democrats have accused Trump of bribing Zelenskiy by conditioning the release of nearly $400 million in military aid to Zelenskiy's publicly announcing the investigations Trump sought. The effort did not come to pass, however, as the Trump administration released the hold on Sept. 11, two days after Congress was alerted to the whistleblower complaint. Republicans have argued that the actions are not impeachable because the aid was released without Zelenskiy's having to announce the investigations.

"Most importantly, the Ukrainians — as far as investigations go — never had to do anything to get the aid released," Rep. Jim Jordan, R-Ohio, said on CBS's "Face the Nation."

In his testimony Wednesday, Taylor said Trump's withholding of the military aid to help his political campaign was "illogical" and "crazy."

On "Fox News Sunday," Rep. Steve Scalise, R-La., responded by saying "the problem with that is it didn't happen."

Scalise added that if Democrats want to impeach Trump, "shouldn't it be based on something that actually happened?"

Rep. Mike Turner, R-Ohio, said on CNN's "State of the Union" that "of course" trading foreign aid for politics favors was "alarming."

"As I've said from the beginning, I think this is not OK," said Turner, a member of the Intelligence Committee. "The president of the United States shouldn't even in the original phone call be on the phone with the president of another country and raise his political opponent. So, no, this is not OK."

But Turner lamented the process by which Democrats were conducting the impeachment inquiry and, pointing to Holmes' testimony, said the newly disclosed call wasn't "scandalous" because Trump essentially said the same thing in the July 25 call, a summary of which was released by the White House.

Turner was also asked about Trump's tweet bashing the ousted U.S. ambassador to Ukraine, Marie Yovanovitch, during her testimony on Friday — commentary that Yovanovitch said moments later was "intimidating" and that Democrats have said amounts to witness intimidation.

"I think, along with most people, I find the president's tweets generally unfortunate," Turner said before criticizing Intelligence Chairman Adam Schiff, D-Calif., adding, "It's certainly not impeachable, and it's certainly not criminal, and it's certainly not witness intimidation."

CNN's Jake Tapper countered, saying that if Yovanovitch found Trump's comment intimidating, "is it not possible that she held back or shaded her answers because she didn't want to upset the most powerful person in the universe any further?"

"Well, I think you overstate Donald Trump's powers, hopefully," Turner said, adding he did not believe Yovanovitch's testimony to have been "inhibited."