By Sara Murray, CNN

(CNN) -- Top White House aides, lawmakers, donors and political consultants are privately asking whether President Donald Trump realizes that losing the House next year could put his presidency in peril.

In more than a dozen interviews, Republicans inside and outside the White House told CNN conversations are ramping up behind the scenes about whether Trump fully grasps that his feuds with members of his own party and shortage of legislative achievements could soon put the fate of his presidency at risk.

Donors who trekked to Jackson Hole, Wyoming, in support of House Speaker Paul Ryan were treated to a slide show late this summer to fundraise off those very fears, according to multiple attendees. Among the slides: An overview of the Democrats who would be tapped to lead key committees if the GOP loses control, including Rep. Elijah Cummings as the head of the House Oversight Committee.

To some attendees, the subtext was clear. If Republicans forfeit the House, Democrats will almost certainly create a spectacle that will derail conservatives' agenda and the remainder of Trump's first term -- a spectacle complete with a raft of new subpoenas, a spotlight on the Russia investigation and, many are convinced, impeachment proceedings.

"When Democrats take control of the House they will absolutely move for articles of impeachment," one Trump confidant predicted.

Alex Conant, a partner at GOP public affairs firm Firehouse Strategies, said Trump should focus on protecting his own party.

"The number one thing Trump should be doing to save his presidency is helping congressional Republicans maintain their majorities," Conant said. "Instead he's allowing his allies like Steve Bannon to really undermine Republican reelection campaigns. It's just reckless and politically naive considering how devastating it would be to his presidency."

Conant served in George W. Bush's White House when Democrats swept control of the House and Senate in the 2006 midterm elections -- and remembers the constant stream of investigations and subpoenas, a stream he said is sure to look more like a deluge in the Trump administration.

"It just cripples your agenda. You're constantly forced to play defense," Conant said.

The primary problem

Republican handwringing over losing control of the House has played out largely in public. But in the hushed conversations that follow, Republicans have wondered whether Trump fully grasps the misery Democrats could unleash on his presidency.

A number of Republicans asked not to have their names used in order to speak candidly about a sensitive topic.

"If we lose the House, he could get impeached. Do you think he understands that?" one top GOP donor recalled an exasperated Republican senator saying privately.

"Won't it be ironic that Steve Bannon helped get the President elected and impeached?" another top Republican official said in a moment of venting.

Bannon, who served in the White House as Trump's chief strategist before he was fired in August, is planning to field primary challengers against nearly every Republican senator up for reelection.

"Right now, it's a season of war against a GOP establishment," Bannon proclaimed at the socially conservative Values Voter Summit over the weekend.

It's the latest in a string of political calculations that are set to backfire on the President, some Republicans warned.

"It will be on steroids, the amount of lawyers, investigations, inspector generals that come out of the woodwork" if Democrats win back the House, predicted Sara Fagen, who served as Bush's White House political director. "It will be very debilitating in a way they don't understand yet."

Marc Short, director of legislative affairs at the White House, said the White House hasn't resigned itself to the notion of losing the House.

"We don't have a defeatist approach on this," Short said. "There's no doubt that history suggests that there's sort of a recalibration after the first midterm, but I don't think we view it as that means it has to go that way."

And he insisted the President is cognizant of the havoc Democrats could cause if they regain control of the House.

"I think the President's keenly aware of that," Short said, adding that he expects Democrats would move forward with articles of impeachment if they win the majority.

GOP operatives are already envisioning Trump family members and acquaintances being dragged up to Capitol Hill over months to testify.

"Once the House is lost, then it just becomes, 'Let's look into Don Jr.'s tweets, let's subpoena his country club locker,'" one GOP strategist quipped. "Nothing is going to get done."

"It's so much more painful than going right to a proceeding of impeachment," another senior Republican operative added.

Another GOP congressional aide predicted the Democrats would make Trump's life a "living hell."

Top White House officials have openly discussed the threat of impeachment among themselves, multiple sources said. And to many, the risk to Trump's presidency is obvious. But White House personnel are loath to broach the topic with the President, sources said.

"Nobody over there is interested in delivering really bad news to the President on a consistent basis," the GOP operative said, particularly when it comes to the potential for impeachment proceedings. "Like, 'hey, this could be a real thing. You shouldn't be so dismissive about it, because Chuck (Schumer) and Nancy (Pelosi) aren't your friends.'"

The uphill impeachment process

Booting the president out of office is exceedingly difficult, a point conceded by even some of Trump's fiercest critics.

If Democrats win the House, they could vote on articles of impeachment. If at least one of those articles garners a majority vote, the president is technically impeached, as was the case with former President Bill Clinton in 1998.

Then the issue moves to the Senate, which conducts a trial presided over by the Supreme Court's chief justice. If two-thirds of the Senate finds the president guilty, he is removed and the vice president becomes president.

No American president has ever been removed from office via the impeachment and conviction process.

While Trump may not be overly preoccupied with the threat of impeachment, he has been livid about what he sees as Congress' inability to execute his campaign promises.

"The Congress has been frustrating to him," retired Gen. John Kelly, Trump's chief of staff, told reporters in the White House briefing room Thursday, lamenting the sluggish pace of the legislative process. "In his view, the solutions are obvious, whether it's tax cuts and tax reform, health care, infrastructure programs, strengthening our military."

In response to that frustration, the President has begun making as many changes as he can unilaterally. He announced he was ending the Deferred Action for Childhood Arrivals program, which protected young immigrants brought to the US illegally as children.

Last week, he began to chip away at Obamacare with an executive order that overhauls the insurance system. He chased it with an announcement that the administration plans to end subsidies to insurance companies that help low-income Americans pay for health care.

Trump also said he had no intention of certifying Iran's compliance with the nuclear deal, punting the issue to Congress to determine whether to reimpose sanctions on Iran and scrap the deal.

Still, the moves fall short of a signature legislative accomplishment. They also risk charges of hypocrisy after Republicans, including Trump, spent years hammering Obama for governing via pen and phone rather than through Congress.

"The most important factor for how the Republican Party does in 2018 is whether we cut middle class taxes or not," said Corry Bliss, the executive director for the Congressional Leadership Fund and American Action Network. "The Republican Party controls the government and we're going to be judged on delivering results."

Slow progress on the Hill

Trump's approach to governing via executive action highlights the precarious situation the President's team has found itself in, roughly a year before the 2018 midterms, after multiple failed attempts to repeal and replace Obamacare and on the precipice of a tax reform fight that is far from a surefire victory and could easily spill over into next year.

"We're really proud of the successes that he's had so far but they're really limited to the things he controls and oversees directly," Nick Ayers, chief of staff to Vice President Mike Pence, said of the President's accomplishments to a room full of donors recently, according to a recording obtained by Politico. "We're really frustrated with what our Republican Congress has not been able to do."

Even as some of Trump's allies see little culpability on the President's side, many on the opposite end of Pennsylvania Avenue take a different view. They see a President who has done little to sell his agenda since taking office. Instead, he has cut deals with Democrats, sparred with top-ranking Republicans and stood by as Bannon takes aim at sitting senators. All moves that are hindering his legislative progress and, Republicans fear, squandering the GOP's window of opportunity while it controls both the House and Senate.

In his speech to GOP donors, Ayers served up a dim projection for the midterms: "We're on track to get shellacked next year," he said.

He implored donors to "purge" Republican lawmakers who don't line up behind Trump's agenda. And, perhaps in a sign of the West Wing's defiance or political naiveté, he offered a glossy assessment of the President's fate.

"The President's going to be fine," Ayers declared.