Even as Democrats on Wednesday impeached President Trump, they turned their attention to allegations that Republican members of Congress encouraged last week’s attempted insurrection, possibly providing help that enabled the mob who stormed the Capitol.

“Their accomplices in this House will be held responsible,” Rep. Jerrold Nadler (D-N.Y.) said in a speech during the impeachment debate, without mentioning specific members or allegations.

In the days since the Jan. 6 attack, immediately preceded by Trump’s remarks at a rally, a number of Democrats have pointed to speeches, tweets and videos that they have said raised questions about whether the attackers may have been inspired or helped by Republican members of Congress.

Rep. Mikie Sherrill (D-N.J.) said in a Facebook Live broadcast that she saw Republicans “who had groups coming through the Capitol that I saw on Jan. 5 for reconnaissance for the next day.” She said some of her GOP colleagues “abetted” Trump and “incited this violent crowd.”

“I’m going to see that they’re held accountable and, if necessary, ensure that they don’t serve in Congress,” she said.

Sherrill did not identify the Republicans, and she did not respond to a request for comment.

Rep. Mikie Sherrill (D-N.J.) on Jan. 12 alleged that some lawmakers led rioters on a "reconnaissance" mission through the Capitol a day before the Jan. 6 riots. (Congresswoman Mikie Sherrill/ Facebook)

She and other Democrats sent a letter Wednesday asking congressional security officials to investigate what they called “suspicious behavior and access given to visitors” the day before the attack. The letter said that Democratic lawmakers and staffers “witnessed an extremely high number of outside groups” visiting the Capitol, which was unusual because the building has restricted public access since March, when pandemic protocols were enacted. Since then, tourists can enter the Capitol only when brought in by a member of Congress.

Among the visitors, according to the Democrats’ letter, were some who “appeared to be associated with the rally.” Sherrill and the other Democrats asked that any logbooks, videos and facial recognition software be examined to identify visitors and determine if they could be matched with those who stormed the Capitol.

Rep. Debbie Wasserman Schultz (D-Fla.) said in an interview that “I do know that, yes, there were members that gave tours to individuals who participated in the riot.” She said an investigation is needed, adding, “What I don't know is whether they were aware of what their plans were for the next day.”

Two law enforcement officials said they had not yet seen any evidence that members of Congress or their staffers aided the attack, but authorities are aware of such questions and allegations that have been raised by Democratic lawmakers. Like others interviewed for this report, they spoke on the condition of anonymity to discuss ongoing probes.

Democrats have yet to publicly name any of the lawmakers they suspect of leading people through the Capitol who later took part in last week’s riot. But in the last several days, a handful of Republicans have emerged as lightning rods for criticism because of their perceived support for the demonstrations.

Last month, “Stop the Steal” movement organizer Ali Alexander claimed that three House Republicans — Reps. Paul A. Gosar (Ariz.), Andy Biggs (Ariz.) and Mo Brooks (Ala.) helped plan his D.C. rally. Biggs and Brooks denied the insinuation in comments to The Washington Post this week. A spokeswoman for Gosar did not return a request for comment, and attempts to speak with Alexander were unsuccessful.

Democrats also have raised concerns about Rep. Lauren Boebert (R-Colo.), who voiced early support for the demonstrators, likening them to 18th-century American revolutionaries. “Today is 1776,” she wrote on Twitter on the morning of the rally.

Boebert, a new member, has faced criticism and even calls for resignation in her first few days on Capitol Hill over a series of controversial actions. Though she denounced last week’s violence on Monday, 24 hours later she was again making headlines, for refusing to submit to a bag check after setting off one of the metal detectors installed outside the House chamber to improve security.

Boebert previously promised that she would bring a gun to Washington and carry it on Capitol grounds. House members are allowed to keep firearms in their offices; they are not permitted to bring them onto the floor.

A spokesman for Boebert did not respond to a request for comment.

GOP leaders have bristled at the accusations levied by Democrats, accusing the majority party of fostering a “cancel culture” against conservatives.

“Republicans have been consistent; we’ve condemned all the violence, all the time,” Rep. Jim Jordan (R-Ohio) said in a speech during the impeachment debate, from clashes that took place at some Black Lives Matter demonstrations over the summer to the “tragic and terrible events of last week.”

A law enforcement official said investigators are looking at everything that happened inside and outside the U.S. Capitol and will follow any evidence wherever it leads.

As part of their investigation, federal agents have been using many of the defendants’ statements on social media to file initial charges against them. They are also using cellphone records in the U.S. Capitol, which provide a detailed account of whose devices were in the building, including where and when. Many rioters were using their phones throughout the chaos, making it easier for the FBI to build cases not just against them but also other rioters, according to law enforcement officials.

Democrats also launched an effort to punish Brooks, who said during the Jan. 6 rally that preceded the attack that “today is the day that American patriots start taking down names and kicking ass.” He wore a hat that said, “Fire Pelosi.”

Wasserman Schultz on Monday co-sponsored a resolution to censure Brooks for his comments.

A spokesman for Brooks said he “never incited violence, as has been egregiously and falsely claimed by his political opponents and the Fake News Media who distorts Congressman Brooks’ remarks.” The spokesman said that Brooks’s remark about taking names was in the context of winning future elections.

Wasserman Schultz also filed a censure resolution against Rep. Louie Gohmert (R-Tex.). After a judge dismissed a lawsuit filed by Gohmert that sought to overturn the election results, Gohmert said in a television interview, “Basically, in effect, the ruling would be that you’ve got to go to the streets and be as violent as antifa and BLM.” That followed Gohmert’s comment in November that Trump supporters who were dissatisfied with the election should consider a “revolution” like the one that overthrew the leader of Egypt. “If they can do that there, think of what we can do here.”

Wasserman Schultz said in her interview with The Post that she filed her resolutions against Gohmert and Brooks because “they directly brought shame on the integrity of the House” and made comments “that were as good as throwing a match on that tinderbox.”

After his remarks were criticized, Gohmert issued a statement that said, “Violence is not the answer. The appropriate answer is courts and self-governing bodies resolving disputes as intended.” His office did not respond to a request for comment.  

Alice Crites, David A. Fahrenthold and Matt Zapotosky contributed to this report.