(CNN) Democratic lawmakers on Wednesday will begin building a formal political process designed to impeach a President -- a momentous task attempted only three times before in nearly two and a half centuries of US history.

The Democratic-led House Rules Committee will sit at 3 p.m. ET to consider a resolution on the scope and regulations of an inquiry into whether President Donald Trump misused his authority by seeking political favors from Ukraine.

The meeting, ahead of an expected full House vote Thursday, is the first time the Democratic majority will go on the record in their attempt to oust the President -- and is also the first step toward open hearings. It could pave the way for the impeachment of Trump by the end of the year.

A formal path toward that outcome would add perhaps the only missing element of drama to a political era that has seen a President consciously tear at the country's long-accepted political and legal norms, leaving his opponents puzzled about the best way to restrain him.

"The evidence we have already collected paints the picture of a President who abused his power by using multiple levers of government to press a foreign country to interfere in the 2020 election," Rep. Adam Schiff of California, chairman of the House Intelligence Committee, Rep. Jerry Nadler of New York, chairman of the Judiciary Committee, Rep. Eliot Engel of New York, chairman of the Foreign Affairs Committee, and Rep. Carolyn Maloney of New York, acting chairwoman of the Oversight Committee, said Tuesday in a statement.

"Following in the footsteps of previous impeachment inquiries, the next phase will move from closed depositions to open hearings where the American people will learn firsthand about the President's misconduct," the chairs said.

Trump and supporters deny that the President did anything wrong in his dealings with Ukraine and are framing the impeachment attempt as the latest desperate effort by Democrats to overturn a 2016 election result they say the Washington establishment has never accepted.

"They've been trying to impeach the President for the last three years, or get him out of office, and they have been unsuccessful at that," Trump's son-in-law and White House senior adviser, Jared Kushner, said on Tuesday.

"The best thing going for the President is that he hasn't done anything wrong," Kushner told Israel's Channel 13, a CNN affiliate.

Wednesday's Rules Committee meeting is the first step in a process choreographed by the Constitution that currently seems unlikely to lead to Trump's ouster. But if Democrats do vote to impeach him ahead of a trial in the Republican-led Senate, his administration will be stigmatized for posterity. The process is also likely to further test the unity of a polarized nation and set the stage for an election that may ultimately have to decide whether Trump's behavior is acceptable in a President.

Damaging new testimony

The gathering impeachment effort comes amid damaging new testimony by a respected military officer about Trump's alleged scheme to extract political dirt from the Kiev government.

A deposition on Tuesday by Army Lt. Col. Alexander Vindman , who as Trump's top National Security Council Ukraine expert became the first current West Wing official to testify to the inquiry, appeared to back up evidence of problematic behavior by the President offered by other key witnesses.

Vindman testified that he was so alarmed by hearing Trump ask Ukraine's President to investigate a political opponent -- his potential 2020 Democratic rival Joe Biden -- that he twice reported his concerns to a superior.

Vindman was the latest example of a career bureaucrat, foreign service official or military officer testifying before the committees investigating impeachment and showing loyalty to their oaths of office and personal definitions of US national interests rather than a President whose efforts to block the investigation have been frustrated.

These officials are exposing themselves to the fierce attacks of political partisans and could potentially jeopardize their own career prospects within government departments headed by Trump loyalists.

Trump's GOP backers deny the President did anything wrong in Ukraine -- however damning the evidence appears to get -- and are branding the Democratic process an unconstitutional outrage.

Wednesday's rituals are likely to deepen the antipathy on Capitol Hill.

Democrats are already accusing Republicans of trying to expose a whistleblower who drew attention to the scandal. Some conservative commentators, meanwhile, are impugning the patriotism of Vindman, a wounded Iraq War veteran who still carries shrapnel in his body, and other pivotal Democratic witnesses.

Resolution follows GOP pressure

Democrats wrote the resolution that will be before the House Rules Committee on Wednesday following demands from Republicans for a full House vote on impeachment and complaints that the deposition process was taking place behind closed doors.

House Speaker Nancy Pelosi of California insists that Thursday's vote is not a full vote on authorizing an impeachment inquiry as Republicans demanded. Democrats, the Constitution and a recent federal court ruling suggest that such a step is legally unnecessary. But the highly symbolic resolution will make it harder for the President to legally block testimony by witnesses and to withhold evidence, Democratic leaders say.

It includes a commitment for a written Intelligence Committee report to outline the case against the President and would allow for testimony and evidence to be transferred to the House Judiciary Committee, which would write articles of impeachment. Republicans are to be allowed to subpoena witnesses and evidence, though such requests have to be agreed to by the majority or the full committee vote.

The Intelligence Committee is tasked with organizing what could become blockbuster and historic open hearings as Democrats seek to make a case that the President is guilty of gross abuses of power.

The eight-page resolution is heavy with the implications of history.

"Directing certain committees to continue their ongoing investigations as part of the existing House of Representatives inquiry into whether sufficient grounds exist for the House of Representatives to exercise its Constitutional power to impeach Donald John Trump, President of the United States of America, and for other purposes," the text of the resolution reads.

A summary of the measure says it allows the President's counsel to take part in Judiciary Committee proceedings to present his case, and respond to evidence.

But the committee says that "if the President unlawfully refuses to cooperate with congressional requests," then the chairman has discretion to deny requests from the President's lawyers.

Republicans, after spending weeks complaining about the lack of a formal impeachment progress, now argue that the Democratic moves have come too late.

"They're now attempting to sort of put a cloak of legitimacy around this process by saying they're going to bring it to a vote on the floor," House Minority Leader Kevin McCarthy, a California Republican, told reporters on Tuesday.

But the GOP's objections to the process -- and dismissal of witnesses -- typically do not directly address the damaging claims made against the President.

Vindman causes trouble for an earlier witness

Vindman's testimony appeared to include some of the most damaging accusations yet, providing more details of the off-the-books foreign policy operation that Trump was running in Ukraine with the help of his lawyer Rudy Giuliani and several other loyalists.

"I was concerned by the call. I did not think it was proper to demand that a foreign government investigate a US citizen, and I was worried about the implications for the US government's support of Ukraine," Vindman said, according to his opening statement

The top Ukraine expert on the National Security Council also appeared to undermine the veracity of earlier testimony by the US ambassador to the European Union, Gordon Sondland.

Vindman said Sondland had told Ukrainian officials that they needed to deliver "specific investigations" to secure a presidential meeting. He said that he, then-National Security Council Russia expert Fiona Hill and others all expressed alarm at the suggestion. But Sondland testified that officials had never shared any concern about his approach.

That inconsistency means Sondland is likely to be called back to Capitol Hill to testify, perhaps in public.

House Intelligence Chairman Schiff has cautioned that while the next phase of the impeachment inquiry is beginning, his panel has not yet exhausted its list of witness depositions.

Washington is on tenterhooks to see whether Tim Morrison , senior director for Europe and Russia on the National Security Council, will show up for scheduled testimony on Thursday.

And there is still no indication of whether the most high-profile potential witness -- former national security adviser John Bolton, who previous witnesses said had expressed concern about US Ukraine policy, will agree to provide testimony.