After several conservative House Republicans aligned with Trump criticized Republican Conference Chair Liz Cheney -- the No. 3 in GOP leadership -- after she announced she would support impeachment Tuesday evening, Cheney fired back to their calls to step down through reporters on Capitol Hill.

"I'm not going anywhere," she said Wednesday afternoon. "This is a vote of conscience. It's one where there are different views in our conference. But our nation is facing an unprecedented, since the Civil War, constitutional crisis. That's what we need to be focused on. That's where our efforts and attention need to be."

-ABC News' Benjamin Siegel and Mariam Khan

House Minority Leader Kevin McCarthy delivered a speech on the House floor against impeaching Trump, arguing that a vote to impeach would "fan the flames of partisan division" and that instead the president could bear responsibility through a censure resolution.

McCarthy began by condemning last week's attack on the Capitol as "undemocratic, un-American and criminal," and although there to defend him, quickly broke from the president in making the distinction that antifa was not to blame for the violence, as Trump has privately suggested.

"Some say the riots were caused by antifa. There is absolutely no evidence of that. And conservatives should be the first to say so," McCarthy said, calling on his colleagues.

"I believe impeaching the president in such a short timeframe would be a mistake," McCarthy said, notably not directly defending his actions as unimpeachable but taking issue with the timing.

"A vote to impeach will further divide the nation. A vote to impeach will further fan the flames of partisan division," he said. "That doesn't mean the president is free from fault."

McCarthy suggested that "a fact-finding commission and a censure resolution would be prudent" but "unfortunately, that is not where we are today." He stressed it's a time "to unite once again as Americans."

House Judiciary Chairman Rep. Jerry Nadler in his floor remarks said the rioters who stormed the Capitol will be brought to justice. Amid accusations from some members of Congress that other members may have abetted rioters, he said accomplices on the floor will also be held accountable.

"We will bring the rioters to justice. Their accomplices in this house will be held responsible," Nadler said. "But today we must focus on the gravest threat first: President Trump."

Rep Adam Schiff, D-Calif., who was the lead impeachment manager for Trump's last impeachment proceedings said America has endured a Civil War, world wars, the Great Depression and now "a Trumpist and white nationalist insurrection," but the nation will prevail because of those Americans patriotic enough restore it.

"This is one of those moments," Schiff said. "Enough."

Rep. James Clyburn, D-S.C., argued that while Republicans are calling for unity and healing, it was the president who refused to recognize Biden's win, leading to a violent transition of power.

"This president's refusal to participate in the peaceful transfer of power and his role in the incitement of last week's violence poses an existential threat. This threat must be extinguished immediately," Clyburn said.

Rep. Jamie Raskin, D-Md., co-sponsor of the impeachment article, warned of future threats to lawmakers if the president isn't held accountable, stressing, "Every one of us in this room right now could have died."

Rep. Jim Jordan, R-Ohio, one of the president's staunchest supporters, began the House debate for Republicans by opposing impeaching Trump and railing against Democrats for what he called their attempt to "cancel the president."

"We should be focused on bringing the nation together. Instead Democrats are going to impeach the president for a second time, one week, one week before he leaves office. Why? Why? Politics and the fact that they want to cancel the president," he said.

"Impeachment round two. It's always been about getting the president, no matter what. It's an obsession. An obsession that's now broadened. It's not just about impeachment anymore. It's about canceling," he added.

Rep. Tom McClintock, R-Calif., told the chamber, "I cannot think of a more petty, vindictive and gratuitous act than to impeach an already defeated president a week before he is to leave office."

"President-elect Biden's promise to heal the nation becomes a hollow mockery in the harsh reality of this unconstitutional act," he said.

Biden and Vice President-elect Kamala Harris have deflected when asked questions about impeachment, saying the decision is with Congress.

The danger to the public and to law enforcement officers from explosive devices during expected upcoming protests "is substantial," the Federal Bureau of Investigation warned in a new awareness bulletin obtained by ABC News on Friday.

The document is full of photos of devices used in the last eight months against civilian and law enforcement targets during public demonstrations.

"Devices targeting infrastructure also increased following violent activity during this time period," the bulletin states.

The FBI now wants to make first responders aware of what has been deployed in the past and what they might encounter during protests linked to the presidential inauguration on Jan. 20.

"The danger posed to law enforcement officers and the general public from the all the tactics listed is substantial," the bulletin states. "If a suspicious item is reasonably believed to contain explosives, an IED, or other hazardous material, DO NOT touch, tamper with, or move the item. Only bomb disposal personal should handle any suspected devices that are located."

An internal FBI bulletin obtained by ABC News earlier this week stated that armed protests are being planned at all 50 state capitols as well as at the U.S. Capitol in Washington, least through Inauguration Day.

The warning comes after suspected pipe bombs were found last week outside both the Democratic National Committee and the Republican National Committee headquarters, just a few blocks from the Capitol where pro-Trump rioters stormed the building.

-ABC News' Aaron Katersky