The House has adjourned moments after gaveling into a pro forma session after Republicans blocked an effort by Democrats to get unanimous consent to force Vice President Mike Pence to invoke the 25th Amendment.

Majority House Leader Steny Hoyer, D-Md., introduced a request by unanimous consent to bring up the Raskin resolution calling on Pence to mobilize the Cabinet to activate the 25th Amendment -- effectively declaring Trump incapable of executing the duties of his office and making Pence the acting president -- but GOP Rep. Alex Mooney of West Virginia objected to the effort.

The House is expected to return on Tuesday for a full floor vote on the legislation. If Pence does not agree to invoke the 25th Amendment, House Democrats says they'll move forward with impeachment.

Monday's session began with the House clerk reading the formal resignation of House Sergeant at Arms Paul Irving and Timothy Blodgett being sworn in as the new Sergeant at Arms.

Calls for the president's removal come after a mob of pro-Trump supporters breached the Capitol on Wednesday while Congress was voting to certify the electoral votes. The assault on the Capitol left at least five dead, including one Capitol Police officer.

-ABC News' Mariam Khan

Drawing a stark contrast to the divisions in the country that boiled over last week, Biden's inauguration theme is set to be of "America United."

After the swearing-in ceremony and inaugural ceremonies at the U.S. Capitol on Jan. 20, the Biden's, Vice President-elect Kamala Harris and her husband Doug Emhoff will be joined by former President Barack Obama and Michelle Obama, former President George W. Bush and Laura Bush, and former President Bill Clinton and Secretary Hillary Clinton for a visit to Arlington National Cemetery. There, the current and former presidents will visit the Tomb of the Unknown Soldier for a wreath-laying ceremony.

The Presidential Inaugural Committee (PIC) announced in a statement Monday, "at a time of unprecedented crisis and deep divisions, America United reflects the beginning of a new national journey that restores the soul of America, brings the country together, and creates a path to a brighter future."

In addition to hosting a National Day of Service -- "United We Serve" -- and the presidential visit to Arlington, the committee will host "Field of Flags" -- a public art display at the National Mall with 191,500 flags representing every state and territory, and 56 pillars of light, in an effort to represent the American people who are unable to travel to Washington for the event.

The committee said in the release the inauguration "will showcase the American people's resilience, heroism, and unified commitment to coming together as a nation to heal and rebuild so that we emerge as the indomitable force that a united America represents."

-ABC News' Beatrice Peterson

As rioters roamed the Capitol last Wednesday, freshman progressive Rep. Cori Bush tweeted she would introduce a resolution calling for the expulsion of GOP members of Congress who, she said, "incited this domestic terror attack through their attempts to overturn the election."

Bush confirmed in a tweet Sunday she’d be introducing a resolution on the House floor Monday seeking to expel lawmakers who, she said, "tried to overturn the election and incited a white supremacist coup attempt that has left people dead" arguing they violated they the 14th Amendment.

"We can’t have unity without accountability," Bush added.

House Speaker Nancy Pelosi in her letter to colleagues Sunday outlining next steps in removing Trump from office also asked Democrats for their views on Section 3 of the 14th Amendment that calls for the removal of anyone who has "engaged in insurrection or rebellion." The section effectively disqualifies those who engage in insurrection against the Constitution of the United States from holding office.

Similar calls are being made in the Senate with Sen. Sherrod Brown, D-Ohio, calling on the U.S. Senate to expel Sens. Ted Cruz, R-Texas, and Josh Hawley, R-Mo., if the senators refuse to resign in the aftermath of the assault on the Capitol.

With just nine full days left in office, Trump is facing a possible historic second impeachment as House Speaker Nancy Pelosi, in the wake of the Capitol Hill assault, warns if he doesn't resign, or if his Cabinet doesn't move to remove him.

Democrats are taking steps Monday morning in the House to remove Trump, beginning at a pro forma session on the House Floor at 11 a.m.

Majority House Leader Steny Hoyer, D-Md., will request unanimous consent to bring up the "Raskin resolution" which calls on Vice President Mike Pence to ask the president's Cabinet to activate the 25th Amendment -- effectively declaring Trump incapable of executing the duties of his office and making Pence the acting president.

If Hoyer fails to get unanimous consent, with Republicans expected to object, Democrats will hold a private caucus call at 2 p.m. and bring up the legislation again Tuesday to a full floor vote. Then, Pelosi said, in a letter to her colleagues Sunday night, "We are calling on the Vice President to respond within 24 hours," and if he does not, they "will proceed with bringing impeachment legislation to the Floor."

With both resignation and removal by the 25th Amendment unlikely, impeachment legislation -- on one article charging "incitement of insurrection," according to a draft -- will likely hit the House floor Wednesday. Rep. David Cicilline, D-R.I., said on Twitter Sunday night that the article has at least 210 cosponsors.

But Democrats are divided over Democratic Majority Whip Jim Clyburn suggesting over the weekend that the House wait until after Biden's first 100 days to submit the article to the Senate to trigger a trial. And there's almost no chance Senate Majority Leader Mitch McConnell will call the Senate back sooner than Jan. 19.

Democrats like Rep. Alexandria Ocasio Cortez argue despite an inconvenient timeline the process allows Congress an outlet to hold Trump accountable. Pelosi told CBS' "60 Minutes" Sunday, Trump had "done something so serious that there should be prosecution against him."

-ABC News’ Mariam Khan and Benjamin Siegel

Rep. Steve Scalise, R-La. -- the No. 2 Republican in the House -- was the last to speak for the Republican Party, said he opposed the "rushed" impeachment, and emphasized that the Senate will only be able to take up the trial once Trump is out of office.

"I've seen the dark evil of political violence firsthand. And it needs to stop. But all of us need to be unequivocal in calling it out every single time we see it, not just when it comes from the other side of the aisle," he said.

Invoking President Abraham Lincoln, he closed by calling on Americans to unify and "seek higher ground."

House Judiciary Chairman Rep. Jerry Nadler, D-N.Y., quickly responded to his remarks, saying, "We can have all this, and we can have accountability too," before handing off to Majority Leader Rep. Steny Hoyer, D-Md.

Hoyer, in a scathing rebuke of the president, repeated the words of Rep. Liz Cheney and called on his Republicans colleagues to rise to the moment and join her to "reject the vices we abhore."

"It is the first and only physical presence other than the 9/11 attack on this nation -- which came from abroad with a plane aimed at our Capitol dome. This attack was not from abroad. It was as Liz Cheney said, summoned, assembled, and inflamed by the president of the United States of America," he said.

"Last Wednesday, on Jan. 6, the nation and the world watched it shatter to pieces. There could be no mistaking any longer the kind of man sitting in the Oval Office or his intentions and capabilities. The curtain has been pulled back. The office to which he was elected could not temper or reform him," Hoyer said.

"Reject deceit. Reject fear mongering. Reject sedition, tyranny and insurrection," Hoyer said. "Reject one man over fidelity to one's country."

Hoyer noted that soon the House Reading Clerk will call the roll for voting, and added, "Make no mistake, this will be no ordinary roll call."

"These votes will be inscribed on the roll of history -- a record of courage -- and of our commitment to country and Constitution, of our commitment to the rule of law and renewal of that which we inherited and hope to pass on, unbroken, unshattered," he said. "Vote for this -- for America, for our constitution, for democracy, for history."