House Democratic leaders are facing increased resistance from key members of both parties to an investigation into whether the results of an Iowa congressional race won narrowly by a Republican can be overturned by Congress.

Several moderate House Democrats on Monday expressed opposition to or discomfort with Congress taking any action regarding the race. Their statements came after nine of the 10 Republicans who voted to impeach former president Donald Trump over his role in the Jan. 6 attack on the Capitol sent House Speaker Nancy Pelosi (D-Calif.) a letter asking her to call off the investigation, warning it could further erode voters’ confidence in the electoral system.

“As I have said before in connection with the 2020 presidential election, legislators should be heeding states’ certifications of their elections, and unless there is rampant error and substantial evidence thereof, I do not believe it is the role of House members to dictate the outcome of elections,” Rep. Susan Wild (D-Pa.), who represents a competitive district, said in a statement.

The focus of the debate is on the outcome of race in Iowa’s 2nd District, where Republican Mariannette Miller-Meeks was declared the winner over Democrat Rita Hart following a recount in November with a difference of just six votes out of 400,000 cast. Miller-Meeks is now serving as the district’s representative, but Hart has asked the House to overturn the result. Hart alleges that 22 legally cast ballots were not considered during the initial November canvass and subsequent recount, resulting in the tightest congressional electoral outcome in modern history.

The consternation over the Iowa race comes at a time of intense debate over how to revamp voting laws following Trump’s unfounded attacks on the results of the presidential election, where he alleged fraud while never providing evidence to back up such claims.

Both the moderate Democrats and Republicans who signed onto the letter to Pelosi argued that taking action on the Iowa race would only further contribute to the voter cynicism stoked by Trump’s false accusations about the sanctity of the vote.

The House Administration Committee is tasked under the Constitution to consider the appeal made by Hart. After conducting an investigation — which could include depositions — the committee can either recommend dismissal, call a new election or declare a candidate the winner, which would prompt a floor vote for all members to agree on their verdict.

If the committee were to recommend overturning the certified results, Democrats could face defections on the House floor from their own caucus, which could lead to an embarrassing loss for Democratic leaders. Rep. Dean Phillips (Minn.), a moderate Democrat, signaled his opposition to overturning the result on Monday.

“Losing a House election by six votes is painful for Democrats. But overturning it in the House would be even more painful for America,” he wrote on Twitter. “Just because a majority can, does not mean a majority should.”

Five Democratic aides, including those working for vulnerable members in swing districts, acknowledged that while the investigation is constitutionally under the House’s purview, their members do not want have to take a vote to overturn an election after the party spent months condemning many Republicans for supporting Trump’s unfounded attacks on the results of the presidential election.

Some of the aides, who spoke on the condition of anonymity to discuss private deliberations, said a floor vote to overturn the results in Iowa would be a waste of time given that there are already not enough votes in the caucus to do so. Currently, Democrats have 219 members, just two defections could sink any possibility of a passage.

It is likely to take weeks, possibly months, until the House Administration Committee reaches a conclusion. Monday marks the first day that lawyers for Miller-Meeks and Hart must turn over their initial briefs, which include evidence they would like the committee to consider.

Two aides said they hope Pelosi and Rep. Zoe Lofgren (D-Calif.), chairwoman of the Administration Committee, start to hear from enough members to dissuade them from putting any recommendation on the floor.

“Members are looking at why Democrats are even considering bringing this issue up. It puts us in a terrible position politically, especially for front-line Democrats,” one Democratic aide said, referring to members in competitive districts.

In their letter sent to Pelosi, nine of the 10 Republicans who voted to impeach Trump expressed their “extreme dismay” over Democrats challenging a race in Iowa and asked her to call off the investigation.

The letter from the nine Republicans effectively seeks to flip a common Democratic complaint on its head: that the House’s examination of the race serves to bolster false claims by Trump and other Republicans that the country’s elections are rife with fraud. Democrats decried Trump’s futile efforts to challenge his loss in the courts and in Congress, claims that were a part of the Jan. 6 insurrection at the Capitol.

“This action not only sets a dangerous precedent for future elections, it reinforces the false belief by many in our country that our election system is rigged and that certain politicians can change results to fit their whims,” the Republicans wrote.

The signers — including Rep. Liz Cheney (Wyo.), the third-ranking GOP member in the House — also wrote that they rebuked Trump because he “repeatedly refuted the results of a certified election, which led to horrific violence in the Capitol Building on January 6th.”

The other signers were Reps. Jaime Herrera Beutler (Wash.), Adam Kinzinger (Ill.), Fred Upton (Mich.), John Katko (N.Y.), Dan Newhouse (Wash.), Anthony Gonzalez (Ohio), David G. Valadao (Calif.) and Peter Meijer (Mich.). The 10th House Republican to vote for Trump’s impeachment, Rep. Tom Rice (S.C.), did not sign the letter; his office did not respond a request for comment.

The letter marks the first time most of the members have joined forces since agreeing with the article of impeachment charging Trump for “incitement of insurrection” and repeatedly undermining the presidential election results. All but Katko have been censured by their state or local Republican Party for their impeachment vote, and many now face primary challenges because of it. Trump was acquitted in the Senate.

“That was not an easy vote for us politically, but it was the right thing to do,” the members wrote in the letter.

Miller-Meeks was sworn into Congress in January alongside three other members of the Iowa delegation after the Iowa State Board of Canvassers certified the results of the recount.

Hart petitioned the House in December, which has the responsibility under Article 1, Section 5 of the U.S. Constitution to “be the Judge of the Elections, Returns and Qualifications of its own members.” Federal law and House rules specifically give the Administration Committee the jurisdiction to consider such claims.

Her campaign argues that had election workers counted 22 curbside, absentee and provisional ballots during the initial canvass, she would have won by nine votes during the recount. Hart also alleges that the recount board violated Iowa elections law by failing to hand-review write-in ballots and criticized counties for using different counting methods in each precinct.

Republicans are accusing Hart of going straight to the Democratic-controlled House in the hopes that they overturn the election results rather than battling it out in state court.

When asked if there is a scenario where the House could overturn the results of the election earlier this month, Pelosi said “of course.” In response to the letter, her office pointed to comments she made last week on ABC News’ “This Week,” where she pushed back on Republicans claims of hypocrisy.

“For them to call anybody hypocritical about elections when two-thirds of them voted against accepting the presidency of Joe Biden — well, it’s just who they are,” she said.

Contesting elections in the House happens somewhat regularly, though for a small proportion of races overall. Peter Whippy, spokesperson for the House Administration Committee, said there have been 110 elections contested since 1933, which averages about two per Congress. Besides the razor-thin Iowa contest, the House was also asked to weigh in on the 14th district race in Illinois.

Earlier this month, Democrats on the committee voted to throw out a Republican amendment to cease the investigation into the Iowa election — the first indication that they will continue with the review process before making a recommendation to the full House for consideration. Initial briefs from both candidate’s lawyers are due Monday.

“Today, none of us can state with confidence who actually won this election,” Lofgren said during a virtual meeting. “Answering that question is a solemn responsibility of this committee and it is our obligation under federal law and under the Constitution. Our answer must be grounded in hard evidence, not bald assumptions.”

During the Administration Committee’s meeting this month, Rep. Rodney Davis (Ill.) echoed fellow Republicans, including Miller-Meeks, who argued that Hart should have filed her appeal to state courts rather than in the House.

Lofgren said the House has never dismissed a case based on a candidate’s failure to first contest an election.

The three Republicans on the committee argue that the investigation is only a waste of taxpayer money.

 “This is a process we can trust. In fact, we already have,” Davis said. “By moving forward with Rita Hart’s complaint, this committee is calling into question every single member elected under Iowa law, and frankly, each one of us, too.”