A key committee of the United States House of Representatives on Friday approved two articles of impeachment against President Donald Trump.
With the historic vote, the House Judiciary Committee recommended Trump be impeached for obstruction of justice and abuse of power.
The articles now go to the full House, making Trump only the fourth president in US history to face formal changes and possible removal from office.
As Democrats move forward with impeachment charges, here's what to expect next:
1. When will the full House vote?
House Democratic leaders have not announced a day or time for the full House vote, but many expect it to take place next Wednesday.
Impeachment in the 435-member House must be approved with a simple majority.
It is unclear whether any Democrats, particularly those who are running tight re-election campaigns, will sway from their party.
Still, Trump is expected to be impeached. The House would then send the articles of impeachment to the Senate for a trial.
2. What are the articles of impeachment?
Articles of impeachment are formal charges. In the case of Trump, the House will consider two articles of impeachment: abuse of power and obstruction of Congress.
Democrats accuse Trump of pressuring Ukraine to open an investigation the president's political rival and former vice president, Joe Biden, who is also a frontrunner in the 2020 Democratic presidential race. They also charge that the president obstructed their investigation by refusing to comply with subpoenas and directing members of his administration to do the same.
The impeachment inquiry, launched in September following a whistle-blower complaint, was centred on a July 25 phone call during which Trump asked Ukrainian President Volodymyr Zelenskyy to open an investigation into Biden and his son, Hunter, who had served on the board of a Ukrainian gas company. There has been no evidence of wrongdoing by the Bidens.
Zelenskyy speaks during a bilateral meeting with Trump on the sidelines of the 74th session of the United Nations General Assembly [File: Jonathan Ernst/Reuters]
Trump also wanted Zelenskyy to investigate a debunked conspiracy theory that Ukraine, not Russia, interfered in the 2016 US presidential election.
At the time of the call, the Trump administration was withholding nearly $400m in Congress-approved military assistance from Ukraine.
Citing testimony by current and former US officials, Democrats also accuse Trump of leveraging a White House meeting that Zelenskyy wanted in exchange for the investigations.
3. What does Trump say?
Trump has repeatedly denied any wrongdoing and labelled the impeachment investigation a "witch-hunt" and "sham".
He has called the July 25 phone call "perfect", and said there was not "quid pro quo" (Latin for "this for that").
"How do you get Impeached when you have done NOTHING wrong (a perfect call), have created the best economy in the history of our Country, rebuilt our military, fixed the V.A (Choice!), cut Taxes and Regs, protected your 2nd [Amendment], created Jobs, Jobs, and soooo much more? Crazy!" Trump tweeted on Friday just before the House Judiciary Committee voted on the articles of impeachment.
4. If Trump is impeached, when will the Senate hold a trial?
A trial in the Republican-controlled Senate is expected in January. No date has been set, but Senate Majority Leader Mitch McConnell said this week that if the House votes to impeach the president, a trial would be the Senate's "first order of business".
5. What happens during a Senate trial?
The chief justice of the US Supreme Court presides over the trial. Senators consider evidence, hear witnesses and vote to acquit or convict the president.
A two-thirds majority vote is required in the 100-member Senate to convict and remove a president from office. A conviction appears unlikely in the case of Trump.
The Senate is made up of 53 Republicans, 45 Democrats and two independents who caucus with the Democrats. At least 20 Republicans would have to vote with all Democrats and the two independents to remove the president.
McConnell has indicated that he would like swift proceedings, but the president has said he would not mind a full trial, with testimony from a number of witnesses, including Biden and the whistle-blower, whose complaint led to the impeachment inquiry.
On Wednesday, McConnell says he sees two options.
"The House managers would come over, make their arguments. The president's lawyers would then respond, and at that point, the Senate has two choices," he said. "It could go down the path of calling witnesses and basically having another trial; or it could decide - and again, 51 members could make that decision - that they have heard enough and believe they know what would happen and could move to vote on the two articles of impeachment sent over to us by the House. Those are the options. No decisions have been made yet."
6. Who would become president if Trump was removed?
In the unlikely event that the Senate convicts and removes Trump from office, Vice President Mike Pence would become president and complete Trump's term, which ends on January 20, 2021.