House speaker Nancy Pelosi has launched a formal impeachment inquiry against Donald Trump, yielding to mounting pressure from fellow Democrats and plunging a divided nation into an election-year clash between Congress and the president.
The probe focuses partly on whether Mr Trump abused his presidential powers and sought help from a foreign government to undermine Democratic foe Joe Biden and help his own re-election.
Ms Pelosi said such actions would mark a “betrayal of his oath of office” and declared: “No one is above the law.”
The impeachment inquiry, after months of investigations by Democrats of the Trump administration, sets up the party’s most direct and consequential confrontation with the president, injects deep uncertainty into the 2020 election campaign and tests the nation’s constitutional system of checks and balances.
Mr Trump, who thrives on combat, has all but dared Democrats to take this step, confident the spectre of impeachment led by the opposition party will bolster rather than diminish his political support.
“There has been no President in the history of our Country who has been treated so badly as I have,” he tweeted on Wednesday from New York, where he has spent the week meeting with world leaders participating in the annual UN General Assembly.
“The Democrats are frozen with hatred and fear. They get nothing done. This should never be allowed to happen to another President. Witch Hunt!
While Ms Pelosi’s announcement adds weight to the work being done on the oversight committees, the next steps are likely to resemble the past several months of hearings and legal battles — except with the possibility of actual impeachment votes.
Ms Pelosi’s brief statement, delivered without dramatic flourish but in the framework of a constitutional crisis, capped a frenetic week-long stretch on Capitol Hill as details of a classified whistleblower complaint about Mr Trump burst into the open and momentum shifted towards an impeachment probe.
For months, the Democratic leader has tried calming the push for impeachment, saying the House must investigate the facts and let the public decide.
The new drive was led by a group of moderate Democratic legislators from political swing districts, many of them with national security backgrounds and serving in Congress for the first time.
The newcomers are risking their own re-elections but say they could no longer stand idle. Amplifying their call were long-time leaders, including representative John Lewis of Georgia, the civil rights icon often considered the conscience of House Democrats.
“Now is the time to act,” Mr Lewis said in an address to the House. “To delay or to do otherwise would betray the foundation of our democracy.”
At issue are Mr Trump’s actions with Ukraine.
In a summer phone call with Ukrainian President Volodymyr Zelenskiy, he is said to have asked for help investigating former vice president Biden and his son Hunter.
In the days before the call, Mr Trump ordered advisers to freeze 400 million dollars in military aid for Ukraine — prompting speculation that he was holding out the money as leverage for information on the Bidens.
Mr Trump has denied that charge, but acknowledged he blocked the funds, which were later released.
The Trump-Ukraine phone call is part of the whistleblower’s complaint, although the administration has blocked Congress from attaining other details of the report, citing presidential privilege.
Mr Trump has authorised the release of a transcript of the call, which is to be made public on Wednesday.
“You will see it was a very friendly and totally appropriate call,” he said.
The whistleblower’s complaint was being reviewed for classified material and could go to Congress by Thursday, according to a source.
Mr Trump has sought to implicate Mr Biden and his son in the kind of corruption that has long plagued Ukraine. Hunter Biden served on the board of a Ukrainian gas company at the same time his father was leading the Obama administration’s diplomatic dealings with Kiev.
Though the timing raised concerns among anti-corruption advocates, there has been no evidence of wrongdoing by either the former vice president or his son.