WASHINGTON >> Democrats set the stage today for certain House approval of the ground rules lawmakers will use as they consider impeaching President Donald Trump. The chamber braced for a near-party line vote in its first showdown over the inquiry.

There was no doubt that the Democratic-controlled chamber would approve the eight pages of rules on Thursday. But it was unclear exactly how many defectors each party would suffer.

“As much as this president flaunts the Constitution, we are going to protect it,” House Rules Committee Chairman James McGovern, D-Mass., said as his panel debated the procedures.

House Minority Leader Kevin McCarthy told The Associated Press that the package creates “much more of a politically closed system than an open system.”

That echoed Republican complaints that the Democratic-run process has been secretive and tilted against them. Democrats say their plan follows how impeachment efforts against Presidents Richard Nixon and Bill Clinton were run.

The investigation is focused on Trump’s efforts to push Ukraine to investigate his Democratic political opponents by withholding military aid and an Oval Office meeting craved by the country’s new president.

Both parties’ leaders have been rounding up votes as Thursday’s roll call approaches, with each side eager to come as close to unanimity as possible.

Republicans said a solid GOP “no” vote would signal to the Senate that the Democratic push is a partisan crusade against a president they have never liked. McCarthy, R-Calif., said he’s unaware of any Republican even “leaning toward voting for it.”

If the House impeaches Trump, the Senate would decide whether to remove him from office.

Rep. Fred Upton, R-Mich., a moderate who some thought might be open to backing the Democratic rules, said he would oppose them. He complained about the secrecy that Democrats have used and said he would not been pressured by GOP leaders or Trump, with whom he had a drink at a Republican fundraiser Tuesday night.

“You really can’t roll back the clock” from the time the investigation began last month, Upton said.

Democrats were also hoping to stay united to demonstrate solidarity from their most left-wing elements to their most moderate members.

“We all want to just follow the facts, apply the law, be guided by the Constitution, present the truth to the American people, and a vote tomorrow is a step in that direction,” said Rep. Hakeem Jeffries, D-N.Y., a member of the Democratic leadership.

He said he believed “the overwhelming majority” of Democrats would back the measure.

House Speaker Nancy Pelosi, D-Calif., decided to have the vote following weeks of GOP claims that the inquiry was invalid because the chamber has not voted to formally commence the work.

The rules lay out the process by which the House Intelligence Committee — now leading the investigation by deposing diplomats and other officials behind closed doors — would transition to public hearings.

That panel would issue a report and release transcripts of the closed-door interviews it has been conducting with diplomats and other officials with connections to Trump’s interactions with Ukraine.

The Judiciary Committee would then decide whether to recommend that the House impeach Trump — a finding that he should be removed from office.

Republicans could only issue subpoenas for witnesses to appear if the entire panel approved them — in effect giving Democrats veto power over such requests by the GOP.

Attorneys for Trump could participate in the Judiciary Committee proceedings. But in a bid for leverage, panel Chairman Jerrold Nadler, D-N.Y., would be allowed to deny “specific requests” by Trump representatives if the White House continues refusing to provide documents or witnesses sought by Democratic investigators.

The rules also direct House committees “to continue their ongoing investigations” of Trump.

Top Democrats think that language will shield their members from weeks of Republican complaints that the inquiry has been invalid because the House had not formally voted to begin that work.

Republican have said the House took such votes before the impeachments of Presidents Richard Nixon and Bill Clinton. Democrats have said there is no constitutional provision or House rule requiring such a vote.

Senate Majority Leader Mitch McConnell, R-Ky., used a floor speech to go after Pelosi and House Intelligence Committee Chairman Adam Schiff, D-Calif., saying that “instead of setting a high bar, House Democrats seem determined to set a new low.”

McConnell said the resolution would deny the “most basic rights of due process” to Trump such as having his lawyer participate in closed-door depositions by the committee.

Democrats compare the committee’s role in the investigation to a fact-finding grand jury proceeding in which the accused does not have rights to counsel.