BATTLE CREEK, MICHIGAN (AFP, WASHINGTON POST) - United States President Donald Trump railed against a Democratic Party "consumed with hatred" after he was impeached for abuse of power and obstructing Congress.

"While we're creating jobs and fighting for Michigan, the radical Left in Congress is consumed with envy and hatred and rage. You see what's going on," the Republican leader seethed at campaign rally in the state on Wednesday (Dec 18).

"These people are crazy."

Mr Trump said the Democratic Party, which controls the House of Representatives where the votes took place, was "trying to nullify the ballots of tens of millions of patriotic Americans".

Just minutes before becoming the third president ever to be impeached, Mr Trump took the stage as House Intelligence Committee Chairman Adam Schiff - one his Democratic tormentors and targets throughout process - was finishing up his own speech criticising the president's conduct that led the nation to this historic brink.

As Mr Trump began speaking, the House began voting - a striking and surreal split screen for a President who had journeyed 600km from the Capitol but was unable to escape impeachment and the imprint it will leave on his legacy.

"By the way, it doesn't really feel like we're being impeached," Mr Trump said mere moments into his speech, claiming that he did "nothing wrong" and touting the support he has in the Republican Party.

The tableau came after a full day of House debate in Washington over the evening vote to impeach the President, who hunkered down in the White House residence on Wednesday with no public events on his schedule, save the rally - but who weighed in on Twitter no fewer than 49 times.

A rage-filled letter that Mr Trump sent to House Speaker Nancy Pelosi on Tuesday, however, offered an epistolary preview of what Mr Trump began delivering in performative fashion onstage in Michigan on Wednesday night.

The outcome of the political struggle is largely preordained: House Democrats voted to impeach Mr Trump on Wednesday night, but the Republican-controlled Senate probably will vote to acquit him early next year.

Those in Mr Trump's orbit said the President took solace in the display of Republican unity and in regular briefings from his campaign team, who counselled optimism.

The campaign repeatedly showed Mr Trump their impeachment polling and reassured him that, at least in the short term, the process has ignited fund raising, further solidified his core supporters and even helped boost him slightly in some key battleground states, a senior campaign official said.

Perhaps it was not surprising that the impeachment of Mr Trump - who said on Tuesday that he bore "zero" responsibility for his predicament - would ultimately play out not just on separate screens, but across almost entirely separate realities.

By mid-afternoon, as the debate on the House floor raged on, Ms Kellyanne Conway, counsellor to the President, appeared in the White House briefing room, where she did not officially brief the press but stood just to the side of the podium and denounced the impeachment inquiry.

The statements on the House floor, too, took on a tale-of-two-impeachments tone.

Representative Mike Kelly, a Republican from Pennsylvania - who in 2012 generated considerable criticism after comparing the Affordable Care Act's birth control mandate to the bombing of Pearl Harbor - wielded the historical allusion again, saying that Trump's impeachment and Pearl Harbor were both December days "that will live in infamy".

Representative Barry Loudermilk, a Republican from Georgia, seemed to compare Mr Trump to Jesus, who he claimed received a fairer trial than the President before his crucifixion.

"When Jesus was falsely accused of treason, Pontius Pilate gave Jesus the opportunity to face his accusers," Mr Loudermilk said.

"During that sham trial, Pontius Pilate afforded more rights to Jesus than the Democrats have afforded this President in this process."

House Majority Leader Steny Hoyer, a Democrat from Maryland, meanwhile, urged House Republicans to look past partisan politics and instead be "profiles in courage" voting to impeach the President.

Competing realities emerged even from within Mr Trump's own White House. Press secretary Stephanie Grisham claimed the President was "working all day", though a cursory read of Mr Trump's Twitter feed cast doubt on that notion.

His first tweet, as he watched Fox & Friends, came just after 7am, and by mid-afternoon, he had tweeted nearly four dozen times.

He had no publicly scheduled events beyond his rally, though White House officials said he participated in several private meetings, including on the spending package and prescription drug pricing.

Even his fiery Tuesday letter to Ms Pelosi proved something of a Rorschach test, depending on the audience.

The six-page missive contained more than a dozen false and misleading claims, decrying impeachment as "egregious", "terrible" and "illegal", and underscored the starkly personal lens through which Mr Trump views the inquiry.

"You do not know, nor do you care, the great damage and hurt you have inflicted upon wonderful and loving members of my family," he wrote at one point.

At another, he accused Ms Pelosi of offending not just the nation's founders by also Americans of faith "by continually saying 'I pray for the President', when you know this statement is not true, unless it is meant in a negative sense".

Ms Pelosi, its intended recipient, described it as "sick".

A White House official noted that Mr Trump had managed to dominate news coverage with his letter, amplifying the defiant posture he has maintained throughout the process.

"I don't think the tone was new," said the official, who spoke on the condition of anonymity because he was not authorised to discuss the matter publicly. "The letterhead was new but the tone was not."

Other Republicans viewed the letter as not especially productive, but as part of the "normalised crazy" even allies have now come to expect from Mr Trump, said one Republican Senate aide.

Mr Brendan Buck, a long-time former Hill aide who is now a Republican operative, said the historic import of the moment was undermined by the drastically different political perspectives that dominated the proceedings from the outset.

"This debate never felt as weighty as it should because the issues were just no match for the tribalism," he said. "From the very start, the process was predictable and the outcome obvious. And at the end of it all, we're basically right back where we started. There's a stain on his legacy but no appreciable change in the political dynamics."

The most recent previous impeachment, of President Bill Clinton in 1998, played out somewhat differently. Similar to Mr Trump, Mr Clinton decried the "excessive partisanship" and "obsessive animosity" that led to the vote, but he also seemed to acknowledge and accept his reality.

After the House vote was official, he donned a coat and walked to the Rose Garden where, alongside first lady Hillary Clinton and Vice-President Al Gore, he offered his remarks.

"I hope there will be a constitutional and fair means of resolving this matter in a prompt manner," Mr Clinton said, shortly before heading back into the White House to throw a Christmas party. "Meanwhile, I will continue to do the work of the American people."

This time around, almost exactly 21 years to the day of Mr Clinton's impeachment, the split screen dichotomy was on display in ways big and small.

Senator Chris Murphy, a Democrat from Connecticut, shared on Twitter what he called a "true story" of a White House staffer making the round among Senate offices to deliver, as a single holiday package, a copy of Mr Trump's scathing letter to Ms Pelosi alongside two White House Christmas cards - one large white one and one smaller red one with Mr Trump's signature Sharpie scrawl in gold.

"What a day," Mr Murphy concluded.