The U.S. House set Donald Trump on a path toward becoming only the third president in history to be impeached by passing a resolution that kicks off the public phase of their accelerating inquiry.

The House on Thursday voted 232 to 196 along mostly partisan lines to begin open hearings to investigate what Democrats say is an abuse of power by Trump in pressuring the government of Ukraine to undertake an investigation for his own personal political benefit.

All signs point to the House taking a formal vote on articles of impeachment on Trump, possibly before the end of the year. However it would take a two-thirds majority vote in the Republican-controlled Senate to convict him, and therefore remove him from office, an outcome viewed at this point as highly unlikely.

Only two other presidents were impeached: Andrew Johnson in the post Civil War era and Bill Clinton in 1998. In both cases, the Senate failed to convict them. Richard Nixon resigned before the full House voted on articles of impeachment.

“No one comes to Congress to impeach a president,” House Speaker Nancy Pelosi said before the vote, but that lawmakers had a duty. “Proudly, we all raised our hand to protect the Constitution of the United States. That is what this vote today is all about.”

Republicans complained that the entire process has been tainted.

”At least today the majority’s admitting what we have known all along -- that the House was not following an appropriate process for impeachment,” Republican Representative Tom Cole said on the House floor.

Trump’s spokeswoman said after the vote that Pelosi and the Democrats are pursuing impeachment at the expense of legislating on behalf of voters even though the president “has done nothing wrong.”

“Nancy Pelosi and the Democrats’ unhinged obsession with this illegitimate impeachment proceeding does not hurt President Trump; it hurts the American people,” White House Press Secretary Stephanie Grisham said in a statement.

Constitutional Question

Only two Democrats joined all Republicans present in opposing the measure, Minnesota’s Collin Peterson and New Jersey‘s Jeff Van Drew. Michigan Representative Justin Amash, a Republican turned independent who has been a Trump critic, voted for the resolution.

Pelosi, who took the unusual step of presiding over the vote, said that a decision to impeach Trump “has not been made.” She and other Democrats cast it as a somber occasion.

”This a sad day for our country,” said Representative Jim McGovern, the Massachusetts Democrat who as Rules chairman introduced the resolution. “We are not here in some partisan exercise we are here because the facts compel us to be here.”

The acrimony may only widen as the process toward a more public airing of the details of Trump‘s pressure on Ukraine to investigate Democrats and Joe Biden, a potential challenger to the president in the 2020 election. With many of the facts already confirmed publicly by White House documents and Trump himself, the ultimate question for lawmakers to decide will be whether that conduct is impeachable.

House Republicans have firmly said it is not.

Representative Jim Jordan of Ohio, the top Republican on the House Oversight and Reform Committee, Democrats are trying to impeach the president 13 months before the 2020 election based on “a complaint from an anonymous whistle-blower with no first-hand knowledge with a bias against the president.”

Trump has lashed out against Democrats throughout the inquiry. On Thursday he tweeted that the process was harming stock prices.

Many Democrats initially said they expect the process to be wrapped up by December, sending the impeachment to the Republican-led Senate for trial. Some members have privately said that timeline could slip into next year. Trial in the Senate almost certainly would extend into 2020, an election year.

The resolution doesn’t establish a deadline for the investigation. It directs six House committees to continue investigating different aspects of Trump’s administration, business and associates, with the Intelligence Committee leading the probe of the Ukraine-related allegations. The Intelligence panel, together with the Oversight and Foreign Affairs committees, has been hearing private depositions for about month, which will continue. Public hearings could begin in two weeks.

Intelligence Chairman Adam Schiff, who has become the Democrats’ public face in the inquiry, said the next phase of the investigation is “one in which the American people will be able to hear from the witnesses first-hand.”

Material gathered during this investigation phase would be turned over to the Judiciary Committee, where Chairman Jerrold Nadler, a New York Democrat, would hold additional hearings in which Trump or his lawyers could participate. The Judiciary Committee would be responsible for drafting any articles of impeachment.

Cole called the process laid out in the resolution unfair to the president, the House and the American people.

“The process laid out in the resolution before us is different from the process used for both President Nixon in 1974 and President Clinton in 1998,” Cole said.

Senate Majority Leader Mitch McConnell, the Kentucky Republican who will shape the Senate trial should the House impeach Trump, said the resolution denies the “most basic rights of due process.”