GOP senator: Trump has changed presidency 'not necessarily toward the positive'

Johnson added that former President Clinton had also shifted the "behavior and the standard of the presidency."
"It's unfortunate. I revere our Constitution. I revere these institutions, including the office of the presidency. It would be nice if everybody conducted themselves, I guess, the way we would here in Wisconsin," Johnson continued. 
Johnson was asked about Trump's behavior, but didn't point to a specific incident during the interview. His comments come as Congress is locked in an impeachment fight fueled by the president's interactions with the leader of Ukraine.
Johnson, who has emerged as one of Trump's most vocal supporters on Ukraine, said on Monday that "there has been a concerted effort from Day 1 to sabotage this administration." 
"I don't agree with everything he's doing, but I have to give him a great deal of credit," Johnson said. 
The White House last week released a partial transcript of Trump's call with Ukrainian President Volodymyr Zelensky. In the call, according to the document, Trump asked Zelensky to work with his personal attorney Rudy GiulianiRudy GiulianiRand Paul calls for probe of Democrats over Ukraine letter Sunday shows — Officials rush to Trump's defense on Syria, sanctions Cruz: 'Of course' it's not appropriate to ask China to investigate Bidens MORE, and expressed hope that he “can look into” former Vice President Joe BidenJoe BidenTrump hits Fox News's Chris Wallace over Ukraine coverage Schiff: Whistleblower testimony might not be necessary Trump warns Democrats will lose House seats over impeachment MORE and his son.
Johnson said on Monday that there was no "quid pro quo" in the Trump call, but that he has "a lot of questions" about Ukraine and Democrats. 
"Everybody says well there's no evidence, all these things have been debunked. ... [But] I have all kinds of questions dating back to Hillary ClintonHillary Diane Rodham ClintonVideo of fake Trump shooting members of media shown at his Miami resort: report Ronan Farrow exposes how the media protect the powerful Kamala Harris to Trump Jr.: 'You wouldn't know a joke if one raised you' MORE's email scandal," Johnson said.