The U.S. House of Representatives has gaveled in to consider the second impeachment of President Trump.

Democrats formally introduced an impeachment resolution Monday, charging Trump with "incitement of insurrection" after he told his supporters at a “Save America Rally” to march on the Capitol during Congress’ joint session to count Electoral College votes on Jan. 6.

"He also willfully made statements that, in context, encouraged — and foreseeably resulted in — lawless action at the Capitol, such as: "if you don't fight like hell you're not going to have a country anymore,'" the resolution reads.

“Thus incited by President Trump, members of the crowd he had addressed, in an attempt to, among other objectives, interfere with the Joint Session's solemn constitutional duty to certify the results of the 2020 Presidential election, unlawfully breached and vandalized the Capitol, injured and killed law enforcement personnel, menaced Members of Congress, the Vice President, and Congressional personnel, and engaged in other violent, deadly, destructive and seditious acts," it continues.

"In all this, President Trump gravely endangered the security of the United States and its institutions of Government. He threatened the integrity of the democratic system, interfered with the peaceful transition of power, and imperiled a coequal branch of Government. He thereby betrayed his trust as President, to the manifest injury of the people of the United States," it goes on.

The impeachment article also cited Trump's call with the Georgia Republican secretary of state where he urged him to "find" enough votes for Trump to win the state -- along with the Constitution's 14th Amendment, noting that it "prohibits any person who has 'engaged in insurrection or rebellion against' the United States" from holding office.

As House lawmakers arrived on Capitol Hill Wednesday, they were greeted by the sight of National Guard members dispersed throughout the Capitol complex before debate kicked off -- a stark sight from last week when Capitol Police were found outnumbered.

Expecting the article to pass the House later Wednesday, Speaker Nancy Pelosi is planning to send the article of impeachment over to the Senate next week, according to a source involved in the Democratic leadership deliberations.

This would leave the Senate no choice but to immediately move towards a trial. The exact timing will depend on whether Majority Leader Mitch McConnell decides to call the Senate back in session early -- which he's said he wouldn't do. Under Senate rules, the Senate cannot officially receive any message or bill or resolution from the House unless the Senate is in session, and the chamber is not scheduled to be back until Jan. 19.

But in preparation for that time, Pelosi has named nine members to serve as impeachment managers to argue the case in the Senate to remove Trump from office over his role in last week’s Capitol riot.

Rep. Jamie Raskin, D-Md., a former constitutional law professor who co-authored the article and whose family was present at the Capitol last Wednesday, one day after burying Raskin's son who took his own life, will serve as the lead impeachment manager.

The other managers -- one of rarest assignments for a House member -- are Democratic Reps. Diana DeGette, Colo., David Cicilline, R.I., Joaquin Castro, Texas, Eric Swalwell, Calif., Ted Lieu Calif., Joe Neguse, Colo., Madeleine Dean, Pa., and Del. Stacey Plaskett, Virgin Islands.

"It is their constitutional and patriotic duty to present the case for the President’s impeachment and removal. They will do so guided by their great love of country, determination to protect our democracy and loyalty to our oath to the Constitution," Pelosi said in a statement Tuesday night.

The impeachment managers are a different set from those tapped by Pelosi one year ago for Trump’s first impeachment trial -- then led by Rep. Adam Schiff, D-Calif. During that effort, managers argued the case to remove Trump for pressuring Ukraine’s president to promise to investigate Biden and his son, Hunter.

-ABC News' Jonathan Karl and Chad Murray

The House of Representatives is poised to impeach President Trump for a second time on Wednesday for "incitement of insurrection," exactly one week after a violent siege on the U.S. Capitol left five people dead.

House Democrats have the votes to impeach Trump, who will become the first and only president in U.S. history to be impeached twice.

And in a turn of events, at least five House Republicans -- including No. 3 Rep. Liz Cheney -- have announced they, too, will vote to impeach Trump, even though no Republicans supported the effort during Trump's first impeachment proceedings related to the Ukraine matter in 2019. The other House lawmakers who say they'll vote to remove Trump include GOP Reps. John Katko, R-N.Y., Adam Kinzinger, R-Ill., Fred Upton, Mich., and Jaime Herrera Beutler, R-Wash.

House GOP leadership said they would not encourage members to vote for or against Democrats' impeachment push, according to House leadership aides, but to "vote their conscience."

In the Senate, Majority Leader Mitch McConnell has not said if he would vote to convict or whether he'd hold a trial in the Senate, ABC News has learned, but he has privately indicated he believes impeaching Trump could make it easier to rid the Republican Party of Trumpism.

-ABC News' Mariam Khan

President Trump, one week ago, encouraged thousands of his supporters to march on Capitol Hill, firing them up with baseless claims of election fraud and instructing them to "fight like hell" in order to "stop the steal,” while Congress affirmed Biden’s electoral vote victory. That day ended in a violent attack on one of the most revered buildings in America.

One week later, Trump finds himself on track to become the first president in American history to be impeached twice as the House of Representatives is scheduled to convene at 9 a.m. Wednesday to debate a rule, then debate on one article of impeachment charging the president with "incitement of insurrection." A final vote is expected later in the day.

Republicans are expected to argue Trump's rhetoric ahead of the mob Wednesday doesn't arise to an impeachable offense, and Democrats are expected to blast those 139 House Republicans who still objected to election results after the roughly six-hour siege.

With at least 218 House Democrats and five House Republicans announcing they’ll vote to impeach the president, a trial in the Senate is imminent. Half of the country's presidential impeachment trials will then belong to Trump.

While House Speaker Nancy Pelosi has not publicly indicated when the House would send the article of impeachment to the Senate after its expected passage, she plans to send it to the Senate next week, according to a source involved in the Democratic leadership deliberations on the matter.

Senate Majority Leader Mitch McConnell has said already he won't bring back the Senate from recess before Jan. 19 -- a day before Biden's inauguration. While McConnell has not said if he would vote to convict or whether he'd hold a trial in the Senate, ABC News has learned, he has privately indicated he believes impeaching Trump could make it easier to rid the Republican Party of Trumpism.

Branding his presidency as a "time to heal," both Biden and Vice President-elect Kamala Harris have deflected impeachment questions to Congress.-- but with confirmations for Cabinet picks and priorities to pass additional coronavirus relief potentially coinciding with Trump’s impeachment trial in the Senate, it’s unclear how Biden -- or the U.S. Senate -- will divide their agendas.

The number of National Guard troops deployed around next week's inauguration could rise from at least 10,000 to 15,000, the National Guard’s top general said Monday.

"Support requests from the Secret Service, Capitol Police and Park Police have been authorized to provide up to 15,000 Guard members to meet current and future support requirements," Gen. Daniel Hokanson, the chief of the National Guard Bureau, told reporters on a phone briefing. "They are troops that have been requested to support security, logistics liaison and communication missions."

Hokanson said that there are currently 6,200 Guardsmen in the District, and there would be 10,000 in place by Saturday.

The National Guard has always participated in inaugurations, and there were 9,000 members on hand last year, but because of the coronavirus pandemic, the number had been reduced to 5,000 for 2021. Last week's insurrection at the Capitol changed those plans, and Pentagon spokesperson Jonathan Hoffman additionally made clear that the Guardsmen will be remaining in Washington after Inauguration Day.

"We're not looking at Jan. 20 as the last day and people will pack up and go home at the conclusion of all the events," he said. "There will be some elements that will remain for a brief period to ensure safety and security in the days following the inauguration as well."

Hokanson, the chief of the National Guard Bureau, said no decision has been made yet about whether to arm the Guardsmen but characterized that possibility as an "ongoing discussion."

"Obviously, we're very concerned that we want our individuals to be have the right to self defense," he said.

-ABC News' Luis Martinez