Rooney, a member of the House Foreign Affairs Committee at the center of the inquiry, said Friday that he had not yet come to a conclusion on whether the President committed a crime that compels his removal from office, a striking view among House Republicans defensive of Trump.

The Florida Republican saidthat Mick Mulvaney, the acting White House chief of staff confirmed Thursday what Trump had denied , that the President engaged in a quid pro quo with Ukraine. Rooney also said he was eager to learn from the witnesses coming in next week.

"Every time one of these ambassadors comes and talks, we learn a lot more," the congressman said.

Rooney is not a typical rank-and-file House Republican. Before winning his first election in 2016, the 65-year-old wealthy businessman's company oversaw construction projects including not only the presidential libraries for both George H. W. Bush and George W. Bush, and the stadiums for the Texas Rangers, Dallas Cowboys and Houston Texans, but the Capitol Visitor's Center, where the witnesses of the investigation dash to enter a secure facility and give their testimonies. He is on now at least his third career, after serving as the US ambassador to the Holy See under the last GOP president.

The President has gone after other critics from his own party, including Sen. Mitt Romney of Utah, whom Trump in one Twitter post called "a pompous 'ass.'" He added "#IMPEACHMITTROMNEY" on another. But Rooney doesn't seem to be concerned.

"What's he going to do to me? He can say bad things but it's -- it just is what it is," said the congressman. "Let's just let the facts speak."

Rooney did acknowledge that some Republicans might be afraid of being rebuked by the party if they expressed skepticism about the President, saying "it might be the end of things for me...depending on how things go."

"I didn't take this job to keep it," he said.

'He's not here to waste time'

The next day, Rooney announced his retirement on Fox News.

"I've done what I came to do," he said.

After receiving a government whistleblower's complaint last month , Democrats have alleged Trump used his public office for personal gain, holding up $391 million in military aid to Ukraine and then pressuring its leader on a July 25 phone call to investigate both a political rival and a conspiracy theory related to the 2016 election.

They've been particularly focused on the first ask, an investigation into former Vice President Joe Biden and his son Hunter, who sat on the board of a Ukrainian energy company, Burisma Holdings, whose owner had been probed by the former Ukrainian general prosecutor. There is no evidence of wrongdoing by either Joe or Hunter Biden.

They launched an impeachment inquiry in the House, gathering evidence from text messages between US diplomats and the sworn testimony of current and former officials. Other key witnesses are expected to testify in private before the House panels next week.

But so far, few Republicans have joined Democrats in even considering that the President committed a crime. Many GOP congressmen say there was no quid pro quo between Trump and Volodymyr Zelensky on that now-famous July call , while others say Trump's conduct was inappropriate but not impeachable.

Rooney had been a defender of the President following the investigation of Russian interference of the 2016 election. In December 2017, Rooney said he was "pretty frustrated" with FBI officials whom he believed displayed bias during the probe.

Now he is "still thinking about" whether the President's actions regarding Ukraine rose to a high crime or misdemeanor.

"I'm not considering anything right now other than getting all the facts and learning more about it," Rooney said. "I'm a business guy, okay? I'm used to being open to all points of view -- and making the best decision I can. But there's a lot of water still to flow down under the bridge on this thing."

Rooney has been a relatively obscure member in the halls of Congress, pushing for initiatives that would benefit his district, like more funding for the Herbert Hoover Dike and Everglades restoration, while discussing US foreign policy through his perch on the relevant committee. Like other Republicans in Congress, Rooney recently criticized Trump's decision to pull US troops from northern Syria as a "huge mistake."

Republican Rep. Mario Diaz-Balart of Florida said Rooney is a "total straight-shooter."

"He's not here to waste time," he added.

He's in the minority of the House, and neither a rabble-rouser nor a part of the leadership team. When asked by a reporter if he had any anecdotes to share about Rooney, Rep. Charlie Crist, a Democrat of Florida, asked whether the article would be for the local newspaper.

Rooney has carved out a reputation for not being shy in breaking from the party, particularly on environmental issues. He's one of the few House Republicans devoted to combating climate change. He supports a tax on carbon emissions and is a critic of the state's sugar industry. And he is one of about a dozen House Republicans to vote against Trump's emergency declaration diverting billions of dollars away from military construction projects towards the wall.

A House Republican leadership aide told CNN, "Rooney has always been somewhat of a rogue member and the idea that the views he's expressing here are felt by a wider swath of House Republicans should be dismissed."

Rooney is free from much political pressure due in part to his vast personal wealth, driven by his success as the CEO of the investment company Rooney Holdings, the majority owner of Manhattan Construction Company.

But the transition from business to elected official has not been entirely pleasant.

"This is kind of a frustrating job for me," Rooney said. "I come from a world of action, decisions, putting your money down and seeing what happens. This is a world of talk. It's very difficult for me to just stand up and talk."

House Speaker Nancy Pelosi poses during a ceremonial swearing-in with Rooney, at right, on Capitol Hill in Washington in January.

A former ambassador

The congressman's experience as a former ambassador in the George W. Bush administration has given him an appreciation for the witnesses who come before him. He said he's eager to hear from acting ambassador to Ukraine Bill Taylor next week, whom he called "a very well respected career diplomat."

"It's painful to me to see this kind of amateur diplomacy, riding roughshod over our State Department apparatus," Rooney said. "I've got great respect for the professional diplomats that protect America around the world."

When asked about the State Department officials coming in as witnesses, Rooney said "these are not partisan people" but "professional diplomats."

Rooney has also taken issue with Mulvaney's defense of the President's actions. The acting White House chief of staff said on Thursday that the Trump administration "held up the money" for Ukraine because the President wanted to investigate "corruption" related to a conspiracy theory involving the whereabouts of the Democratic National Committee's computer server hacked by Russians during the last presidential campaign.

Democrats have argued that even if no favors were exchanged, Trump committed an impeachable offense in asking a foreign country to interfere in a US election. But Mulvaney's comments undermined a key GOP stance that the President's actions were not impeachable, asserting that there was no quid pro quo and the aid eventually went through to Ukraine. Hours after the news conference on Thursday, Mulvaney released a statement reversing his prior comments.

Rooney said Friday he was "shocked" by Mulvaney's initial comments.

"The only thing I can assume is he meant what he had to say — that there was a quid pro quo on this stuff," said Rooney, adding that Mulvaney could not change his position.

"It's not an Etch A Sketch," said Rooney

This story has been updated with additional developments Saturday.