Democrats have rammed a package of ground rules for their impeachment inquiry of US President Donald Trump through a sharply divided House of Representatives.
It is the chamber’s first formal vote in a fight that could stretch into the 2020 election year.
The tally was 232-196, with all Republicans against the resolution and just two Democratic defectors joining them.
The vote laid down the rules as politicians transition from weeks of closed-door interviews with witnesses to public hearings, and ultimately to possible votes on whether to recommend Mr Trump’s removal from office.
The action also took on more than a technical meaning, with each party aware that the impeachment effort looms as a defining issue for next year’s presidential and congressional campaigns.
The vote, which occurred on Halloween, drew a familiar Twitter retort from Mr Trump: “The greatest Witch Hunt in American History!”
White House press secretary Stephanie Grisham accused House Speaker Nancy Pelosi and the Democrats of an “unhinged obsession with this illegitimate impeachment proceeding”.
During the debate, Democrats spoke of politicians’ duty to defend the constitution, while Republicans cast the process as a skewed attempt to railroad a president whom Democrats have detested since before he took office.
“What is at stake in all this is nothing less than our democracy,” said Ms Pelosi.
Underscoring her point, she addressed the House with a poster of the American flag beside her and began her remarks by reading the opening lines of the preamble to the constitution.
House Minority Leader Kevin McCarthy said Mr Trump had done nothing impeachable and accused Democrats of trying to remove him “because they are scared they cannot defeat him at the ballot box”.
Number three House Republican leader Steve Scalise accused Democrats of imposing “Soviet-style rules”, speaking in front of a bright red poster depicting St Basil’s Cathedral in Moscow’s Red Square.
Independent Representative Justin Amash, who left the Republican Party earlier this year after saying he was open to considering whether Mr Trump should be impeached, also backed the measure.
The investigation is focused on Mr Trump’s efforts to push Ukraine to investigate his Democratic political opponents by withholding military aid and an Oval Office meeting craved by the country’s new president.
Democrats said the procedures – which give them the ability to curb the president’s lawyers from calling witnesses – are similar to rules used during the impeachment proceedings of presidents Richard Nixon and Bill Clinton.
Republicans complained they were skewed against Mr Trump.
It is likely to take weeks or more before the House decides whether to vote on actually impeaching Mr Trump.
If the House does vote for impeachment, the Senate would hold a trial to decide whether to remove the president from office.
Ms Pelosi decided to have the vote following weeks of Republican claims that the inquiry was invalid because the chamber had not voted to formally commence the work.
The rules lay out how the House intelligence committee – now leading the investigation by deposing diplomats and other officials behind closed doors – would transition to public hearings.
That panel would issue a report and release transcripts of the closed-door interviews it has been conducting.
The judiciary committee would then decide whether to recommend that the House impeach Mr Trump.
According to the rules for hearings, Republicans could only issue subpoenas for witnesses to appear if the entire panel approved them – in effect giving Democrats veto power.
Lawyers for Mr Trump could participate in the judiciary committee proceedings.
But in a bid for leverage, panel chairman Jerrold Nadler would be allowed to deny “specific requests” by Trump representatives if the White House continued refusing to provide documents or witnesses sought by Democratic investigators.
The rules also direct House committees “to continue their ongoing investigations” of Mr Trump.
Top Democrats think that language will shield their members from weeks of Republican complaints that the inquiry has been invalid because the House had not formally voted to begin that work.
Democrats have said there is no constitutional provision or House rule requiring such a vote.