Already one of President Donald Trump’s most prominent defenders, U.S. Rep. Doug Collins now has a chance to shift the tone of the House’s impeachment investigation even as it seems more likely the president will face charges.

That probe enters a new phase this week when the House Judiciary Committee meets to discuss whether the Intelligence Committee has provided evidence proving Trump broke his oath of office. And that puts Collins, the top-ranking Republican on Judiciary, at center stage. He is the GOP member who will have the most influence on how meetings are conducted and will become the party’s most prominent voice on impeachment.

The Gainesville representative has already proved himself to be effective in communicating pro-Trump talking points while poking holes in Democrats’ challenges to the president’s decision-making. He said he welcomes the role of protecting Trump against impeachment.

“It’s easy to argue when you have truth on your side,” Collins told The Atlanta Journal-Constitution recently. “Whether that shows me as a defender of the president, which it is, or whether that shows me and our Republican conference is tired of the attacks from the Democrats on a duly-elected president for what is no reason for impeachment, then so be it.”

Democrats say Collins and other Republicans are too willing to defend the president at all costs, even when there is evidence of wrongdoing. And they worry he will use committee procedures and rules to thwart the investigation come Wednesday.

U.S. Rep. Hakeem Jeffries, D-New York, has served as Collins’ partner on criminal justice issues among others. But on impeachment they find themselves directly opposed. Jeffries, the House Democratic Caucus chairman, is a primary spokesman for defending the process and purpose of the impeachment probe.

Jeffries appeared on "Fox News Sunday" after Collins and responded to some of his critiques about the investigation and upcoming hearing. Jeffries said Collins should be more concerned about the witnesses who lent credibility to the accusation that Trump wanted to withhold aid from Ukraine until its leaders agreed to investigate his political opponents.

“All of whom confirmed the central allegations here of the wrongdoing engaged in by the president with respect to pressuring a foreign government to target an American citizen,” Jeffries said. “That is the abuse of power that we are concerned about. That act undermined America’s national security.”

Collins' willingness to spar with Democrats to Trump's benefit could give the representative an advantage, too. It may bolster his campaign for the U.S. Senate even as Gov. Brian Kemp prepares to appoint someone else to the soon-to-be-vacated seat.

Brian Robinson, a GOP strategist who served as a spokesman for Gov. Nathan Deal, said the hearings give Collins a chance to prove how he earned Trump’s backing.

“President Trump has strongly pushed for Doug’s appointment, and the nation is about to see why,” Robinson said. “Doug’s a fierce and effective advocate for the president.”

Kemp has indicated he plans to appoint businesswoman Kelly Loeffler to succeed U.S. Sen. Johnny Isakson, even knowing that Collins is Trump’s preferred choice. That choice has opened Kemp up to criticism from conservatives, made more damaging because Collins is considering running in the November 2020 special election against Kemp’s appointee.

Collins said he has not decided whether to run for the Senate.

"I have a big job to do in the next three weeks, and that's impeachment," he told "Fox News Sunday's" Chris Wallace. "We'll wait to see where the governor goes with this pick, and we'll have a decision to make after that."

Deciding to run as a pro-Trump candidate against Kemp’s appointee could have negative consequences, too. Collins runs the risk of turning off the same people the governor is hoping will support GOP candidates in 2020: mainly white women living in the Atlanta suburbs.

“The risk to Collins is this is going to be very public, more so than I think a lot of the hearings have been,” Georgia State University political science professor Amy Steigerwalt said. “And there is a question of how is he going to be perceived.”

Collins’ position as the top Republican on the Judiciary Committee allows him to make an opening and closing statement at each meeting and gives him greater leeway to question people called to testify. That gives the representative plenty of opportunities to get his message across, Steigerwalt said.

“He is going to play a very prominent role, and part of that role is setting the agenda for how the information is going to be communicated as well as interpreted,” she said.

It’s not just his position on the Judiciary Committee that allows Collins to enjoy the impeachment spotlight. He credits his background as an attorney, a chaplain and a veteran with providing him the analytic and communication tools needed to succeed as a GOP leader.

“I have counseled and listened all of my life,” Collins said. “… It helps me clarify situations, clarify my questions and also be able to frame things, hopefully, in ways that people can understand. Because the vast majority of people are going to get 5- to 6-minute soundbites out of this, and it’s my job to put it into very succinct, logical terms that they can understand.”

He has already begun making his case in appearances on Fox News and in letters to U.S. Rep. Jerry Nadler, the Democratic chairman of the Judiciary Committee.

Collins has requested that Trump be allowed to call witnesses as part of this phase of the inquiry and that House Intelligence Committee Chairman Adam Schiff be required to testify. He has also requested access to all evidence collected by the Intelligence Committee, which critics say is a veiled effort to uncover the identity of the whistleblower whose complaint helped launch the impeachment inquiry.

Over the weekend, Collins wrote a letter asking Nadler to add more conservatives to the panel of constitutional experts who will testify at Wednesday’s Judiciary hearing on impeachment.

“Throughout this hurried and partisan impeachment process, I have consistently requested mere fairness from members of the majority,” he wrote. “An equal distribution of experts for the December 4 hearing would be a small concession to demonstrate to the American people this impeachment inquiry is not merely political theater.”

Collins has been here before.

He took a similar role of staunch Trump ally this summer when special counsel Robert Mueller testified before the Judiciary Committee and another House panel. He grilled Mueller and said Democrats had not proved that the president conspired with Russia to interfere in the 2016 election.

Collins helped shape the narrative that Mueller’s report was inconclusive and helped give Trump room to deny wrongdoing, Steigerwalt said.

He describes it as an opening act of sorts. Now, with the upcoming hearing, American people will be used to hearing from him about why Trump deserves the benefit of the doubt over the Democrats who oppose him, Collins said.

“I think that is one thing people can say is that they’re used to seeing me,” he said. “They understand my position. I’ve been tested.”