Republicans who support President Trump say the next three weeks are crucial to determine whether Trump can keep Republicans united behind him or if emerging cracks break open even wider.
Their growing concern is that the White House is not acting with enough urgency to combat the whistleblower fight.
They're calling for a more coordinated but also direct and aggressive strategy, similar to the one used when Republicans defended Brett Kavanaugh when Trump nominated him for the Supreme Court.
"It's not like you have all this time for this to unfold. You've got to be ready for battle right now," said Scott Jennings, who was subpoenaed by the Senate when he worked for Republican George W. Bush and is close to the White House.
"That's why I was comparing it to Kavanaugh. That was a short fight. You know, it happened over a period of weeks. Democrats had their message. They fired their shots. The Republicans were organized. They fired back. And so to me that's really the template here."
Trump has been lashing out at Democrats and reporters, as Republicans have struggled to defend the president for encouraging the Ukrainian government to investigate the son of former Vice President Joe Biden, a potential 2020 rival.
A senior Senate GOP aide expressed confidence that, as it stands, Senate Republicans do not believe Trump's July 25 phone call with the Ukrainian president unto itself is an impeachable offense. The aide spoke on the condition of anonymity to be able to speak freely about strategy and expectations.
At the same time, the aide said there's a realization that this is a volatile, unpredictable political conflict. And there have been "zero" efforts to coordinate messaging with the White House or each other, the aide said.
"Everyone is waiting for the next shoe to drop," the aide said.
The White House has dismissed the need for a war room like the one former President Bill Clinton created in the 1990s during the Monica Lewinsky scandal.
Kellyanne Conway, counselor to the president, insisted there was no need and that Democrats had not proven they met the burden for an impeachment inquiry.
"You're getting that from people who want to create an impeachment war room to get either back in or get through the door in the first place," Conway told reporters. "Why would he do that? Who started the war here? He's the most battle-tested person I've ever met."
For now, Republicans are focusing their message on attacking Democrats as being hungry for impeachment since they regained control of the House following the 2018 midterms.
As part of the process argument, House Minority Leader Kevin McCarthy, R-Calif., sent a letter to House Speaker Nancy Pelosi, D-Calif., on Thursday calling on her to formalize the impeachment inquiry so that there are clear rules of investigation.
"The American people deserve assurance that basic standards of due process will be present," he wrote.
But multiple GOP congressional sources have expressed relief that Congress is in recess right now, where lawmakers are largely inoculated from having to respond to the president's day-to-day allegations in the ongoing investigation.
The week of Oct. 14 will be a pressure test on Republicans to see if that unity can hold or if cracks continue to emerge as the impeachment inquiry continues to consume the news cycle.
Sen. Chuck Grassley of Iowa, the most senior Republican senator, broke from Trump and said the whistleblower should be protected. On Tuesday, Grassley appeared to be blocking GOP efforts to expose the whistleblower.
"This person appears to have followed the whistleblower protection laws and ought to be heard out and protected," Grassley said in a statement. "We should always work to respect whistleblowers."
Thomas Bossert, who served as Trump's first homeland security adviser, revealed more cracks Sunday when he said on ABC News that Trump was pursuing a Ukraine conspiracy that had already been "completely debunked."
On Thursday, former Rep. Carlos Curbelo, a Florida Republican, urged the GOP to "unequivocally" condemn President Trump after he asked Ukraine and China to investigate the Biden family.
"This is unacceptable," Curbelo tweeted. "Republicans must condemn it unequivocally. Time is running out for them to get on the right side of history. Our institutions [are] being diminished in a very dangerous way."
GOP consultant and Trump critic Rory Cooper, a former spokesman for former House Majority Leader Eric Cantor, said congressional Republicans are in a difficult position because it's hard for them to defend Trump's actions on the merits: whether it's acceptable behavior for a president to solicit help from a foreign leader to look into a political opponent.
"I think that's an impossible question for any conservative lawmaker to say 'yes' to, and so they have to argue process and media," Cooper said. " 'The media is being unfair to us; the process is rigged.' That's all they can do."
Cooper also said that while many Republicans will privately stew about the president, there remains no political incentive to cross him.
"The vast majority of Republican lawmakers on the Hill have a transactional relationship with the president," he said, "and a real and deserved threat of a primary if they walk away from him. There's survival involved. It's a lonely place to be out on that limb, opposing him."
House Republican aides have begun holding regular staff briefings over the recess to coordinate messaging and talk strategy.
House Republicans have at least two conference calls scheduled this week: one for members of the leadership whip team on Thursday, and an all-members call on Friday.
A GOP leadership aide said staff are also planning a series of "member education" meetings when they return to brief lawmakers on the impeachment process. Echoing the Senate aide, the House aide said House Republicans do not believe what is known about the July 25 phone call amounts to an impeachable offense.
House Republicans' messaging so far has largely focused on attacking the process, arguing that Pelosi cannot unilaterally declare an impeachment investigation is underway without the authorization of a full House vote.
"I don't buy that this is officially an impeachment inquiry," said former Rep. Tom Davis, R-Va., who once chaired the Oversight Committee and ran the House GOP's operation during the Clinton impeachment process. "The House of Representatives hasn't acted. The speaker has, but she can't declare an impeachment inquiry by fiat."
Davis argued Democrats are vulnerable in possible court challenges over securing testimony and document requests because a judge could take into account that the House has not officially established an impeachment proceeding is underway.
Pelosi has rejected this argument.
"First of all, there's no requirement that there be a floor vote," she told reporters Wednesday, adding: "There's some Republicans that are very nervous about bringing that vote to the floor."
Republican strategist Alex Conant said the next three weeks are a crucial period in which many Americans will be making up their minds about the whole Ukrainian affair. Conant said Republicans need to act now — like in the Kavanaugh fight — if they want to win the messaging war.
"This isn't a case where we're waiting for judges to make up their minds because we are waiting for senators and congressmen," he said, "and to a larger extent the American people as a whole to make up their minds. And people tend to make up their minds pretty quickly, which is why it's going to go quickly and why the next few days are really crucial for the White House to get its message out there and give Republicans something to rally behind."
Most Republicans remain unified behind the president, in large part because of his sky-high approval ratings among GOP voters.
"The Republican base is rabid over this issue," Davis said.
Most Republicans represent districts where Trump remains wildly popular, so there is little motivation to publicly criticize the president. Just three Republicans remain who represent districts Hillary Clinton won in 2016: Reps. Will Hurd of Texas, John Katko of New York and Brian Fitzpatrick of Pennsylvania. Hurd, a frequent critic of Trump, is not seeking reelection in 2020.
Jennings, the former Bush White House staffer, said the president may see the charges as frivolous, but that doesn't mean the process or the politics are frivolous. Jennings said the Republican Party is behind him, but they also need to be better armed to combat the Democrats' message on a daily basis.
"Every day, you need to counterattack," he said. "Every day, you need a countermessage, and every day you have to rally your people to combat that message as best you can. Now, the president has a powerful tool. Social media accounts he uses very successfully to get information out to his people, but that's not really enough."
Republican strategists such as Davis say it's important to remember that the politics of impeachment in the Trump era are unpredictable — and that should make everyone nervous.
"I think we are in very uncharted waters," Davis said, "I don't know how this is going to bounce."