The US Senate has found that the impeachment trial of former President Donald Trump is constitutional, allowing full proceedings to begin.
Mr Trump's defence team argued that he cannot face trial after leaving the White House.
But a 56-44 majority voted in favour of continuing, with a handful of Republicans backing the measure. Mr Trump is accused of "inciting insurrection" when Congress was stormed last month.
Thousands gathered in support of false claims that widespread electoral fraud denied Mr Trump victory in the US presidential election.
Democrats prosecuting the case opened Tuesday's proceedings by showing a video montage of Mr Trump's 6 January speech and the deadly rioting by some of his supporters.
"That's a high crime and misdemeanour," Representative Jamie Raskin of Maryland said of the footage. "If that's not an impeachable offense, then there's no such thing."
Lawyers for the former president argued it was unconstitutional to put a former president through the process at all and accused Democrats of being politically motivated.
The 56-44 split means six Republicans joined Democrats in voting to go ahead with the trial.
Although this shows some bipartisanship, this result implies loyalty toward the former president in his party remains high enough to avoid a conviction.
A two-thirds majority is required to convict Mr Trump in the evenly split 100-seat Senate.
If convicted Mr Trump could be barred from holding office again.
What happened on Tuesday?
Proceedings opened with impeachment managers - the Democrats tasked with leading the prosecution - argue their attempts were legitimate.
In the 10-minute video used in their presentation, Mr Trump was shown telling his supporters to "fight like hell" before they stormed the US Capitol in violence that resulted in five deaths - including a police officer.
Rep Raskin was brought to tears as he recounted fear for his own family's safety during the riot after he was separated from his visiting daughter.