There could still be a way to end Donald Trump's presidency early, according to a Kiwi law expert.
Trump's impeachment means he now faces a trial in the US Senate, which is controlled by his Republican Party colleagues, who have vowed to exonerate him no matter what evidence is presented.
Mitch McConnell, the Senate's top Republican, says there is "no chance" they'll remove Trump, and has openly admitted coordinating with the White House.
Democrat Nancy Pelosi, the Speaker of the House, has threatened to delay the trial until the Senate agrees to "fair" rules.
University of Waikato professor of law Al Gillespie says if Trump's former national security advisor steps up, bombshell reveals could shift the tide:
"The only new thing that could change that majority right now is if one person - John Bolton - became a witness. But Trump right now is in court trying to make sure Bolton cannot testify."
He says if Bolton reveals enough, Trump could lose Republican support. In September Trump claimed he fired Bolton, while Bolton said he quit.
As national security advisor when Trump did the stuff that led to his impeachment, it's believed Bolton could have damning information that could make it difficult for Republicans to continue supporting him.
But Gillespie says Republican voters have valid reasons to keep him in office.
"Their GDP is growing, their inflation is low, their unemployment is almost at an historic low - so many people on the ground think Trump is doing a very good job and they would not want to see him impeached."
With a standoff between Pelosi and the Senate possible, Gillespie says it will be a "complete distraction" for Trump, who wants the trial over quickly before next year's election campaign.
A two-thirds majority will be needed in the Republican-controlled Senate to oust him from office.
"This lawless, partisan impeachment is a political suicide march for the Democrat Party," Trump told supporters in Michigan, as the vote was under way in the House.
"They've been trying to impeach me from day one. They've been trying to impeach me from before I ran."
The only two other Presidents in US history to be impeached were Bill Clinton and Andrew Johnson. Both were acquitted in the Senate. Richard Nixon was going to be impeached, but resigned first.
