Donald Trump is facing a historic second impeachment after Democrats in the House of Representatives formally charged him with one count of “incitement of insurrection” over the Capitol Hill riot. Five people died in the attack last week, including a police officer, which Trump prompted when he told supporters to “fight like hell” in his attempt to overturn election defeat by Joe Biden. Emerging video footage has revealed just how close the mob came to a potentially deadly confrontation with members of Congress. On Monday, security officials scrambled to ensure that Biden’s inauguration next week would not be marred by further violence. The US Secret Service will begin carrying out its special security arrangements for the inauguration this Wednesday, almost a week earlier than originally planned, although on Monday afternoon the acting secretary of homeland security, Chad Wolf, abruptly resigned, just days after calling the Capitol invasion “sickening”. Earlier, ABC News said it had obtained an internal FBI bulletin which detailed plans for “armed protests” and calls for the “storming” of state, local and federal courthouses and buildings across the country if Trump was removed from power before then. On Capitol Hill, the House speaker, Nancy Pelosi, who in an interview on Sunday called Trump “a deranged, unhinged, dangerous president”, initiated a plan in two parts. “The president’s threat to America is urgent, and so too will be our action,” she said. An initial resolution called on Mike Pence, the vice-president, to support removing Trump under the 25th amendment. A clause in the amendment, never before invoked, describes how members of the cabinet can agree to remove a president under extreme circumstances. Pence, a staunch loyalist until the climax of Trump’s effort to overturn the election, has signaled no intention of joining such a move. Republicans in the House duly blocked the Democratic resolution. But it was followed by the introduction of an impeachment article citing “incitement of insurrection”. Trump was charged to have “engaged in high crimes and misdemeanors by inciting violence against the government of the United States” and thus having violated his oath of office. The article cites 14th amendment prohibitions against any person “engaged in insurrection or rebellion against” the US from “hold[ing] any office … under the United States”. The House will debate the charge on Wednesday. The Democratic congressman David Cicilline of Rhode Island, who introduced the measure, tweeted that Democrats now have sufficient votes to pass it and impeach Trump a second time – a first in American history. But for him to be removed would require conviction in the Senate. The Senate is in recess until after the inauguration, and Democratic leaders have said they will not take up impeachment until after the Biden administration has had time to try to have nominees confirmed and to pass key legislation in its first 100 days. President-elect Joe Biden on Monday afternoon said: “I think President Trump should not be in office. Period.” A small number of Republicans in the Senate and House have joined Democrats’ effort to remove Trump. Adam Schiff, the Democratic chairman of the House intelligence committee and a key figure in the first Trump impeachment, tweeted: “Every day Trump stays in office, he’s a threat to our democracy. Congress must act, and with urgency.” But conviction in the Senate would be a long shot, as it was last time the president was impeached. Some Republicans have indicated support this time but about a dozen more will be needed for success. Trump was charged with two articles of impeachment in December 2019 and acquitted in February 2020. If Trump were convicted after he had left office, the Senate could decide to punish him by barring him from seeking office again, as opponents fear is his plan in 2024. Since the attack on the US Capitol, the president has retreated from the public eye and been banned from Facebook and Twitter, condemned by former allies and vowed not to attend Biden’s inauguration on 20 January. His silence was filled by full-throated calls from Democrats for his ejection from office – and meek pushback from some Republicans calling for national “unity” after their attempt to overturn the November election produced one of the most egregious acts of violence on Capitol Hill in two centuries. There are now signs that diehard Trump loyalists are planning to march on the Capitol yet again, on inauguration day, in an event branded online as “A Million Militia March”. The FBI has arrested dozens of participants in last week’s rioting and continued to circulate wanted posters of suspects, potentially dampening participation in another rally. But with nine days to go to the inauguration, officials were planning to secure the area. The mayor of Washington, Muriel Bowser, asked the Department of Homeland Security to put new restrictions in place and urged people to avoid the city on 20 January. The Pentagon, FBI, Secret Service and other agencies were reportedly placed on alert and the national guard said it would increase troops in Washington to at least 10,000 by Saturday. The National Park Service temporarily closed the Washington Monument “in response to credible threats to visitors and park resources”. The inauguration will be attended by Barack and Michelle Obama, George and Laura Bush and Bill and Hillary Clinton. Biden, the incoming Vice-President, Kamala Harris, and their families will be joined by the former presidents and their families in a visit to Arlington national cemetery, ABC reported. Such plans were made as the nation struggled to come to terms with the violence last week in which five died and dozens were injured. On Monday, the 75-year-old New Jersey Democratic congresswoman Bonnie Watson Coleman said she had tested positive for coronavirus and believed she had become infected while locked down for hours at the Capitol during the riot last week with colleagues who were not wearing face masks. Coleman is awaiting a more comprehensive Covid test, noting that she had already received the first shot of the two-dose vaccine.