President Donald Trump became the third US president in history to be impeached after the Democrat-controlled House of Representatives voted heavily along party lines to formally charge him with abuse of power and obstruction of Congress over his conduct towards Ukraine.
Hours after his impeachment, Democrats and Republicans turned to sparring over when and how to conduct the upcoming trial in the Senate, which is likely to go in Mr Trump's favour.
The vote on Wednesday night to charge the President with two articles of impeachment capped a highly partisan series of hearings and debates that will continue with a Senate trial to acquit him, or remove him from office.
At a press conference after the vote, House Speaker Nancy Pelosi declined to commit to a timeline for sending the articles of impeachment to the Senate - which is needed for an impeachment trial to begin - over her concerns that the Republican-held Senate would not conduct the trial fairly.
The move to hold back the articles could indefinitely delay the start of the trial and deny Mr Trump the political victory of exoneration by the Senate.
Threatening to do so also gives the Democrats leverage in getting Senate Majority Leader Mitch McConnell to agree to terms more favourable to them, including allowing key witnesses to testify in the trial. It also gives time for new information to come to light if court rulings go their way.
Republican senators Marco Rubio and Lindsey Graham took to Twitter to blast the potential move as a "partisan political stunt" and "constitutional extortion" that was fundamentally unfair to Mr Trump.
On the Senate floor yesterday, Mr McConnell said the Democrats had rushed forward with a case against Mr Trump that was too weak, which he said was clear when Ms Pelosi "suggested that House Democrats may be too afraid to even transmit their shoddy work product to the Senate".
On Twitter, Mr Trump said "the Do Nothing Party want to Do Nothing with the Articles and not deliver them to the Senate", adding that if the Democrats did so "they would lose by Default!"
Wednesday's votes on the two articles passed by 230 votes to 197, and 229 to 198. Underscoring the deep political divide in the US, no Republican voted to impeach, while all but two Democrats voted for the first article of impeachment and all but three for the second.
Mr Trump is the first impeached president to seek re-election.
Only two other presidents have been impeached in the US' 243 years of history: Andrew Johnson in 1868 and Mr Bill Clinton in 1998. Both were acquitted in the Senate.
At a campaign rally in Battle Creek, Michigan - a state he narrowly won in 2016 - a defiant Mr Trump told supporters just after the House vote: "The country is doing better than ever before. We did nothing wrong."
White House press secretary Stephanie Grisham said in a statement that the President was confident he would be fully exonerated.
Earlier, under the dome of the US Capitol, Democrats and Republicans invoked the nation's founding fathers, quoted the pledge of allegiance, and drew parallels with previous impeachments and past wars as they took turns in an over six-hour debate to sum up their decision on whether to impeach.
"If we do not act now, we would be derelict in our duty. It is tragic that the President's reckless actions make impeachment necessary. He gave us no choice," said House Speaker Nancy Pelosi as she opened the debate on Capitol Hill, while dozens of pro-Trump and pro-impeachment supporters protested outside.
House Intelligence Committee chairman Adam Schiff made the Democratic case for impeachment, accusing Mr Trump of using his public office for personal political gain in pressuring Ukraine to announce an investigation damaging to Democratic front runner Joe Biden in July.
The first article of impeachment charged Mr Trump with abusing his office by suspending military aid and withholding a White House meeting until Ukraine announced an investigation.
The second article of impeachment charged Mr Trump with obstructing Congress by instructing administration officials not to comply with subpoenas.
Republicans condemned the impeachment inquiry as a desperate witch hunt by a party with a vendetta against an undesired president, contending that due process was not followed and the impeachment threshold of high crimes and misdemeanours was not reached.
One thing appears certain: the Senate's 47 Democrats and their allies are unlikely to muster the additional 20 Republican votes needed to end Mr Trump's presidency.