An uneasy détente has emerged between congressional Republicans and Democrats after the Jan. 6 attack, but relationships are badly frayed.WASHINGTON — When a Republican lawmaker approached Representative Veronica Escobar, a Democrat, on the House floor recently with a routine request that she sign on to a resolution he was introducing, she initially refused.Ms. Escobar personally liked the man, a fellow Texan, and she supported his bill. But she held the Republican, who had voted to overturn the results of the 2020 presidential election just hours after rioters stormed the Capitol, partly responsible for the deadly attack and questioned whether she could work with him.Moments after declining, however, Ms. Escobar had second thoughts.“Go ahead and count me in,” Ms. Escobar recalled telling the man, whom she declined to identify in an interview. “But I just want you to know that what you all did — I haven’t gotten past it. And it was wrong, and it was terrible. And it’s not something that I think we should gloss over.”In the immediate aftermath of the assault on the Capitol that left five dead, irate Democrats vowed to punish Republicans for their roles in perpetuating or indulging former President Donald J. Trump’s fiction of a stolen election that motivated the mob that attacked the building. There was talk of cutting off certain Republicans entirely from the legislative process, denying them the basic courtesies and customs that allow the House to function even in polarized times.Democrats introduced a series of measures to censure, investigate and potentially expel members who, in the words of one resolution, “attempted to overturn the results of the election and incited a white supremacist attempted coup.” But the legislation went nowhere and to date no punishment has been levied against any members of Congress for their actions related to Jan. 6.What has unfolded instead has been something of an uneasy détente on Capitol Hill, as Democrats reckon with what they experienced that day and struggle to determine whether they can salvage their relationships with Republicans — some of whom continue to cast doubt on the legitimacy of President Biden’s victory — and whether they even want to try.“I don’t want to permanently close that door,” Ms. Escobar said. “But I can’t walk through it right now.”Republicans have felt the breach as well. Representative Michael Waltz, Republican of Florida, who did not vote to overturn Mr. Biden’s victory but joined a lawsuit challenging the election results, said feelings ran raw after the mob violence at the Capitol.“I had some candid conversations with members that I have a good relationship with. There was a lot of heated emotion,” Mr. Waltz said. Still, he said, “I didn’t experience a freeze.”He recently teamed up with Representative Anthony G. Brown, Democrat of Maryland, to round up 70 Republicans and 70 Democrats for a letter to the Biden administration laying out parameters for an Iran nuclear deal.The dilemma of whether to join such bipartisan efforts is particularly charged for centrist Democrats from conservative-leaning districts, who won office on the promise of working with Republicans but say they find it difficult to accept that some of those same colleagues spread lies that fueled the first invasion of the Capitol since the War of 1812.Adding to the tensions, most Republicans insist that they did nothing wrong, arguing that their push to invalidate the election results was merely an effort to raise concerns about the integrity of the vote. Some have reacted angrily to Democrats’ moves to punish them.Days after Representative Jason Smith, Republican of Missouri, voted to throw out electoral votes for Mr. Biden, an aide to Representative Cindy Axne, Democrat of Iowa, curtly rebuffed a request from his office to discuss writing insurance legislation together.Representative Jason Smith, Republican of Missouri, voted to throw out electoral votes for President Biden.Stefani Reynolds for The New York Times“Our office is declining to work with your office at this time, given your boss’s position on the election,” the aide wrote in an email to an aide to Mr. Smith.Mr. Smith later sought to turn the tables on Ms. Axne, posting the email on his official Twitter account after she highlighted her work with Republicans.“That’s odd,” Mr. Smith wrote, appending a screenshot of the exchange. “This is the last message my staff got from you. Are you no longer kicking Republicans off your bills?”A spokesman for Mr. Smith did not respond to a request to elaborate on the incident.Representative Abigail Spanberger, Democrat of Virginia, who was in the House gallery on Jan. 6, said she had taken it upon herself to try to facilitate a reconciliation — or at least an airing out of differences.“It’s been a really challenging time,” she said. “Literally, people were murdered in our workplace. For some people, that is deeply troublesome, and for some people, they want to move on faster than others are ready.”In the days after the attack, the wounds it laid bare seemed almost too deep to heal. As the mob tore closer to lawmakers on Jan. 6, Representative Dean Phillips, a mild-mannered Minnesota Democrat known for fostering bipartisan relationships, shouted at Republicans, “This is because of you!”Afterward, lawmakers nearly came to blows on the House floor and got into heated arguments in the hallways. Some Democrats were so nervous that their Republican colleagues might draw weapons on the floor that House leaders set up metal detectors outside the chamber, drawing loud protests from gun-toting lawmakers in the Republican Party.Representative Zoe Lofgren, Democrat of California and the chairwoman of the Administration Committee, released a review of Republicans’ incendiary remarks on social media before the attack.Some Democrats, particularly the most progressive lawmakers from safe districts who rarely found occasion to work with Republicans even before the riot, have pressed to penalize the G.O.P. systematically in its aftermath, arguing that there can be no return to normalcy. A spreadsheet of Republicans who voted to overturn the election, outlining how many states’ electoral votes they moved to cast out, has circulated widely among Democratic offices.Lawmakers and their staff members were evacuated from the House chamber on Jan. 6.Andrew Harnik/Associated PressBut there has been little action to truly cut Republicans out of the work of Congress. When Representative Sean Casten of Illinois moved to punish a Republican who had voted to overturn the election results by forcing a recorded vote on his bill to rename a post office — the kind of measure that normally sails through unchallenged — only 15 other Democrats joined Mr. Casten in opposing it. As some rank-and-file Democrats sought to expel the Republican conspiracy theorist Marjorie Taylor Greene of Georgia from the House, Speaker Nancy Pelosi said the move was “not a leadership position.” (Leaders did, however, take the unusual step of stripping Ms. Greene of her committee seats.)The reluctance stems, at least in part, from politics. Democrats owe their majority to a group of lawmakers from competitive districts who say their constituents elected them to work with Republicans to get legislation done.“Retreating or closing myself off to any kind of conversations or working with folks on the other side of the aisle — it doesn’t feel like an option for me,” said Representative Sharice Davids, the only Democrat in the Kansas congressional delegation. “Even when it feels hard.”Representative Susan Wild, Democrat of Pennsylvania, was in the House gallery on Jan. 6 and had what she believed was a panic attack as she crouched on the floor and heard the noise from the mob grow closer. But she said in an interview that she had “moved past the election issue,” adding that she was “not one to hold grudges.”“I haven’t talked to a single Republican about that day. Nothing. At all,” said Ms. Wild, who has resumed working with Pennsylvania Republicans on legislation, even though most of them voted to overturn the election. “I don’t want it to get in the way of other things that I want to work on with them. I know that it would, because I would be angry.”Many House Republicans have refrained from discussing the attack, while some have tried to rewrite history and argue that they never claimed the election was “stolen,” despite their objections. One tried to remove mentions of the assault from a resolution honoring the police officers who defended the Capitol that day. Some have continued to deny that Mr. Biden was legitimately elected, while still others have sought to deflect attention from the riot or downplay the factors that drove it.When the House Armed Services Committee held a hearing recently to examine domestic extremism in the military, Representative Pat Fallon, Republican of Texas, complained that the session was “political theater” and a waste of the panel’s time.The chairman, Representative Adam Smith of Washington, tartly replied that the topic deserved discussion, since “20 percent of the people that have been arrested from the Capitol Hill riots had a history of serving in the military.”Representative Rodney Davis of Illinois, the top Republican on the Administration Committee, objected to Ms. Lofgren’s report cataloging his colleagues’ incendiary social media posts. One Democrat, Representative Brad Schneider of Illinois, recently removed a Republican from a bill the two had worked on together for years, in line with his new policy of collaborating only with lawmakers who publicly state that Mr. Biden was legitimately elected.But he said he had drawn some optimism from a blunt conversation with Representative Jody B. Hice, Republican of Georgia, whom he has worked with on environmental issues, about a speech Mr. Hice gave questioning his state’s electoral votes for Mr. Biden.Mr. Hice said in a statement that he was proud that he and Mr. Schneider could “put aside our differences” on “many of the hot-button political debates of the day” to work together.Still, Mr. Schneider said that many other Republicans were still questioning Mr. Biden’s legitimacy — and that some were even continuing to put lawmakers at risk with incendiary remarks.“The fact that there is — how many at this point? — that it’s not an insignificant number who are still trying to have it both ways, makes it harder to get something done in Congress,” he said. More