US Democrats began the process of impeaching President Donald Trump for a historic second time, accusing him of "incitement of insurrection" over his supporters' deadly storming of the US Capitol.
The move - which threatens to torpedo the single-term president's future political ambitions - could make for a frenetic culmination of four years of controversy ahead of Joe Biden's January 20 inauguration.
Democrats introduced a resolution in the House of Representatives calling for Vice President Mike Pence and the cabinet to remove Mr Trump - who has been absent from the public spotlight for days - as unfit for office under the Constitution's 25th amendment.
But Republicans blocked an immediate adoption of the resolution, forcing a vote, and Democrats followed up by introducing an article of impeachment of Mr Trump for "incitement of insurrection".
Speaker Nancy Pelosi hit out at House Republicans, accusing them of enabling Mr Trump's "unhinged, unstable and deranged acts of sedition to continue."
"Their complicity endangers America, erodes our Democracy, and it must end," she said in a statement.
Ms Pelosi said the House would vote Tuesday on the demand for Mr Pence to invoke the 25th Amendment, and would give him 24 hours to respond.
After that, she said, Democrats would move forward with bringing impeachment legislation to the floor.
Mr Trump has been largely silent in recent days - making few statements and holding no news conferences. Twitter, his favored public platform, has banned him for language that could incite violence.
He plans to travel to Texas on Tuesday in one of his final trips as president, reportedly to claim success in delivering on his pledge to build a border wall to keep immigrants from Mexico out of the US.
As Democrats began to act, the US Capitol building was open to lawmakers and staff but under tight security and ringed by a metal fence after Wednesday's assault by Trump supporters that left five people dead.
Historic second impeachment
Inside, some windows and doors that were broken and breached by rioters remained boarded up with plywood, while reinforced glass on the outside doors near the Rotunda bore cracks from repeated battering.
The attack on Congress shook the core of American democracy and drew international condemnation. It has ignited a new effort to remove Mr Trump, who is accused of whipping up the mob into storming the capitol where lawmakers were certifying Mr Biden's 3 November win.
Mr Trump was already impeached once by the Democratic-controlled House in December 2019 for pressuring the Ukrainian president to dig up political dirt on Mr Biden.
He was acquitted by the Republican-majority Senate.
If the House again votes to impeach, Mr Trump would be the first US leader to be formally charged for a second time with "high crimes and misdemeanors."
President Donald Trump and first lady Melania Trump board Air Force One at Andrews Air Force Base, 23 December, 2020. Source: AP
Even with time running short, Democrats likely have the votes in the House to impeach Mr Trump again and Congressman David Cicilline, who introduced the resolution, told reporters afterward he expects it will find Republican backing.
"This was an attempted coup, to overthrow the government, and we have a responsibility as Congress to respond to that," said Cicilline.
But although two Republican Senators - Pat Toomey and Lisa Murkowski - have urged Mr Trump to resign, Democrats are unlikely to muster the two-thirds majority needed to convict Mr Trump in the 100-member Senate and remove him from office.
'Attempted coup'
The impeachment effort is nevertheless seen by Democrats as worthwhile.
Although any conviction would likely occur after Mr Trump has already left office, it would lead to a secondary vote on banning Mr Trump, who is thought to be considering a run in 2024, from holding federal public office again.
Authorities are still seeking to arrest more Trump supporters who stormed the Capitol following a rally by the president repeating false claims that he had lost the election to Biden due to fraud.
Capitol security has been stepped up and Trump supporters have threatened new action in coming days both in Washington and state capitol buildings.
Senate rules mean the upper chamber would likely be unable to open an impeachment trial before 19 January .
Some Democrats, for their part, have expressed concern that a Senate trial would overshadow and hamper Mr Biden's efforts to quickly lay out his agenda, starting with the fight against the coronavirus and the need to support the economy.
