House Speaker Nancy Pelosi (D-San Francisco) announced the impeachment inquiry of President Donald Trump Sept. 24 for pressuring the Ukranian president to investigate Democratic presidential nominee Joe Biden ahead of the 2020 presidential election.

“The actions of the Trump presidency revealed dishonorable facts of betrayal of his oath of office and betrayal of our national security and betrayal of the integrity of our elections,” Pelosi announced.

Trump asked the Ukrainian president to investigate Biden, accusing the former vice president of stopping a former Ukrainian prosecutor from investigating a company under the direction of his son Hunter Biden, according to a transcript of a phone call between President Trump and the president of Ukraine, released to the public Sept. 25.

“There’s a lot of talk about Biden’s son, that Biden stopped the prosecution, and a lot of people want to find out about that so whatever you can do with the attorney general would be great,” Trump said, according to the transcript.

The former prosecutor general of Ukraine, Viktor Shokin, ended the investigation of Hunter Biden after finding no wrongdoing, his successor Yuri Lutsenko told the LA Times in a Sept. 28 interview.

The Ukrainian parliament then voted to fire Shokin in 2016 due to his reputation for allowing corruption amid pressure domestically and from several western countries, including the U.S. Joe Biden was among the many calling for the embattled prosecutor’s removal from power.

“…it’s not enough to set up a new anti-corruption bureau and establish a special prosecutor fighting corruption,” Joe Biden said to the Ukrainian parliament in a Dec. 9, 2015, speech. “The Office of the General Prosecutor desperately needs reform.”

The transcript sparked concern among top Democrats that Trump wished to exchange political favors with a foreign power to improve his 2020 election bid in exchange for $400 million in aid.

 Impeachment

 Six committees are conducting investigations into potential wrongdoing by Trump. 

Pelosi in her announcement directed those committees to continue their investigations under the umbrella of the impeachment inquiry. They will gather documents, conduct interviews and hear from witnesses.

“It can be helpful to think of this as similar to but different than the structure of a criminal investigation,” SF State political science professor Rebecca Eissler said.

 If a committee determines that Trump committed a crime, then the House of Representatives will vote to decide whether to impeach him. At least 223 Democratic representatives have publicly stated their support for impeachment — enough for the process to continue.

 Once the committees finish collecting evidence and file a formal accusation, a trial would begin. The committees would hand their evidence to a prosecutor, and the case would leave the House and enter the Senate, where 67 senators must vote to charge the president as guilty to indict him.

Senate Majority Leader Mitch McConnell (R-KY) could simply refuse to have a trial and end the impeachment process, Eissler said. However, McConnell told NPR that “if it [impeachment] were to happen, the Senate has no choice. If the House were to act, the senate immediately goes into a trial.”

“This is like a proceeding in a courthouse where the hundred members of the Senate are the jury, and the Chief Justice of the Supreme Court, John Roberts, would be the judge in this trial,” Eissler said.

Sixty-seven senators must vote to charge the president as guilty in order to remove him from office. If they don’t, the impeachment process will end.