Donald Trump is maintaining his innocence as his Senate impeachment trial officially gets under way.
Just hours after the trial opened, the President posted an all-caps tweet reiterating that the phone call which started it all was "perfect".
Trump will be formally notified that the Senate has convened and asked to file his response to the charges by 6pm ET. His lawyers have until Monday to file their brief.
The trial opened with a ceremonial reading of the House-passed articles, followed by a pledge from the senators to deliver "impartial justice".
The ceremony marked the official start of the trial — only the third of its type against a sitting President in US history.
Trump is accused of abuse of power and obstruction of Congress for trying to pressure Ukrainian leader Volodymyr Zelensky over the phone to open an investigation into his political rival Joe Biden.
He is also accused of impeding Congress' investigation into him by preventing witnesses from testifying and defying subpoenas for documentary evidence.
The President continues to deny wrongdoing on both fronts.
Today's convention was largely symbolic, with the real action to begin next week when the Senate returns to vote on rules for the trial next Tuesday.
Based on current impeachment rules, the trial will run from Monday to Saturday every week, and may take several weeks.
Now bear in mind, Trump is probably not going anywhere, as the Senate is controlled by the Republican Party. But that doesn't mean the vote's not important, nor does it mean we won't see any surprises.
WHY IS TRUMP UNLIKELY TO LOSE HIS JOB?
It takes two separate votes to remove a sitting President from the top job.
Last month the US House of Representatives, controlled by the Democrats, voted to impeach Trump. The resolution passed by 228 votes to 193.
The Senate, controlled by Trump's Republican Party, will now have the final say to determine whether he is convicted and removed from office.
But here, a minimum two-thirds of senators would have to vote to remove the President.
Republicans are in control of the Senate, with 53 senators to the Democrats' 47. For the Senate to convict Trump and complete the process, 20 members of Trump's own party would be required to vote against a man who is easily their best shot at another four years in government. That's just … not gonna happen.
So why are the Democrats bothering? Shouldn't they be focusing on a unified strategy for their own political campaign?
On one hand, yes. But bear in mind the President has been accused of extremely serious crimes — seeking to bribe a foreign power to dig up dirt on his leading political opponent.
Trump was also accused of withholding almost US$400 million in military aid from Ukraine in exchange for the investigation into Biden.
The Democrats believe the President needs to be held responsible for these alleged abuses of power.
"If we allow a President to be above the law, we do so surely at the peril of our republic," Pelosi said last month. "The President leaves us no choice but to act because he is trying to corrupt once again the election for his own benefit."
This also could have implications for the Democrats in the upcoming November election.
Democrats have been struggling to sway independents and voters in key battleground states so far, but they're hoping shining a spotlight on the President's misdeeds will inspire people who want him removed from office to get out and vote next year.
While the results of the impeachment hearings are unlikely to sway rusted-on Trump supporters, only 29 per cent of Americans identify as Republican according to Gallup polling.