Trump faces a single charge -- “incitement of insurrection” — after the deadly Capitol riot in an impeachment resolution that the House will begin debating Wednesday.

At the same time, the FBI warned ominously Monday of potential armed protests in Washington and many states by Trump loyalists ahead of President-elect Joe Biden’s inauguration, Jan. 20. In a dark foreshadowing, the Washington Monument was closed to the public amid the threats of disruption. Acting Homeland Security Secretary Chad Wolf abruptly resigned.

It all added up to stunning final moments for Trump’s presidency as Democrats and a growing number of Republicans declare he is unfit for office and could do more damage after inciting a mob that violently ransacked the U.S. Capitol last Wednesday.

Also read: Impeachment looming, Democrats urge Pence to help oust Trump

“President Trump gravely endangered the security of the United States and its institutions of Government,” reads the four-page impeachment bill.

“He will remain a threat to national security, democracy, and the Constitution if allowed to remain in office,” it reads.

House Speaker Nancy Pelosi is summoning lawmakers back to Washington for votes, and Democrats aren’t the only ones who say Trump needs to go.

Also read: Pelosi says House will impeach Trump unless VP forces ouster

Republican Sen. Pat Toomey of Pennsylvania joined GOP Sen. Lisa Murkowski of Alaska over the weekend in calling for Trump to “go away as soon as possible.”

Rep. Liz Cheney, R-Wyo., encouraged House GOP colleagues late Monday to “vote your conscience,” according to a person granted anonymity to discuss the private call. She has spoken critically of Trump’s actions, but has not said publicly how she will vote.

Also read: Trump remains defiant amid calls to resign

Pending impeachment, Democrats called on Vice President Mike Pence and the Cabinet to invoke their constitutional authority under the 25th Amendment to remove Trump from office before Inauguration Day.

Their Democrats’ House resolution was blocked by Republicans. However, the full House is to hold a roll call vote on it Tuesday, and it is expected to pass. After that, Pelosi said, Pence will have 24 hours to respond. Next would be the impeachment proceedings.

Pence has given no indication he is ready to proceed on a course involving the 25th Amendment.

Also read: Democrats plan lightning Trump impeachment, want him out now

He and Trump met late Monday for the first time since the Capitol attack, a senior administration official said.

Trump and Pence had a “good conversation” in the Oval Office discussing the week ahead, and they pledged to continue working for the remainder of their terms, said the official, who spoke on condition of anonymity to discuss the private meeting.

No member of the Cabinet has publicly called for Trump to be removed from office though the 25th Amendment.

As security tightened, Biden said Monday he was “not afraid” of taking the oath of office outside — as is traditionally done at the Capitol’s west steps, one of the areas where people stormed the building.

As for the rioters, Biden said, “It is critically important that there’ll be a real serious focus on holding those folks who engaged in sedition and threatening the lives, defacing public property, caused great damage -- that they be held accountable.”

Biden said he’s had conversations with senators ahead of a possible impeachment trial, which some have worried would cloud the opening days of his administration.

Senate Democratic leader Chuck Schumer was exploring ways to immediately convene the Senate for the trial as soon as the House acts, though Republican leader Mitch McConnell would need to agree. The president-elect suggested splitting the Senate’s time, perhaps “go a half day on dealing with impeachment, a half day on getting my people nominated and confirmed in the Senate, as well as moving on the package” for more COVID relief.

As Congress briefly resumed Monday, an uneasiness swept government. More lawmakers tested positive for COVID-19 after sheltering during the siege. And new security officials were quickly installed after the Capitol police chief and others were ousted in fallout from the attack on the iconic dome of democracy. Some GOP lawmakers, including Missouri Sen. Josh Hawley, faced public blowback for their efforts on the day of the riot trying to overturn Biden’s election.

House Majority Leader Steny Hoyer, D-Md., offered the 25th Amendment resolution during Monday’s brief session. It was blocked by Rep. Alex Mooney, R-W.Va., as other GOP lawmakers stood by him.

Pelosi said the Republicans were enabling Trump’s “unhinged, unstable and deranged acts of sedition to continue. Their complicity endangers America, erodes our Democracy, and it must end.”

However, House Republican leader Kevin McCarthy, a Trump ally, said in a letter to colleagues that “impeachment at this time would have the opposite effect of bringing our country together.”

He said he would review possible censure of the president. But House Republicans are split and a few may vote to impeach.

The impeachment bill from Reps. David Cicilline of Rhode Island, Ted Lieu of California, Jamie Raskin of Maryland and and Jerrold Nadler of New York draws from Trump’s own false statements about his election defeat to Biden.

Judges across the country, including some nominated by Trump, have repeatedly dismissed cases challenging the election results, and Attorney General William Barr, a Trump ally, has said there was no sign of widespread fraud.

The impeachment legislation also details Trump’s pressure on state officials in Georgia to “find” him more votes, as well as his White House rally ahead of the Capitol siege, in which he encouraged thousands of supporters last Wednesday to “fight like hell” and march to the building.

The mob overpowered police, broke through security lines and windows and rampaged through the Capitol, forcing lawmakers to scatter as they were finalizing Biden’s victory over Trump in the Electoral College.

While some have questioned impeaching the president so close to the end of his term, Democrats and others argue he must be held accountable and prevented from holding future public office. He would be the only president twice impeached.

House Democrats have been considering a strategy to delay for 100 days sending articles of impeachment to the Senate for trial, to allow Biden to focus on other priorities.

Also read: Pelosi seeks to curb Trump's nuclear power, plans to impeach

There is precedent for pursuing impeachment after an official leaves office. In 1876, during the Ulysses Grant administration, War Secretary William Belknap was impeached by the House the day he resigned, and the Senate convened a trial months later. He was acquitted.

Sen. Ben Sasse, R-Neb., said he would take a look at any articles that the House sent over. Rep. Adam Kinzinger, R-Ill., a frequent Trump critic, said he would “vote the right way” if the matter were put in front of him.