Transcript for Impact of Capitol violence will reverberate through all levels of government: Part 2
Reporter: Insurrection and chaos at the U.S. Capitol. An attempted overthrow of democracy like we've never seen in American history. Sheer terror as lawmakers duck and cover. While a violent pro-trump mob stormed the seat of the U.S. Government -- It's a horrifying day for America. Bloodshed, mob violence, fear among the people's elected representative doing the people's business that they might be killed. Tear gas wafting through the chamber of the house of representatives. It could not have been a greater contrast and a greater tragedy for that constitution. Reporter: Shots fired inside the house chamber. I don't know if that's a fire -- Reporter: Doors and windows bashed in. Truly no words to describe the scene happening behind me here as trump supporters have taken over the west lawn here. Reporter: All this happening as the U.S. Congress is supposed to be certifying President-Elect Joe Biden's victory. Threatening the safety of duly elected officials, it's not protests, it's insurrection. Reporter: When the day dawned in D.C., the nation expected a very different kind of drama to play out. Today was supposed to be one of those days in the democratic process that we don't even notice. This is the verdict of our people. Then the congress counts them. Reporter: By mid-morning, thousands of trump supporters were gathering for a save America March not far from the white house, there to protest president trump's November election defeat, just 14 days before Joe Biden's inauguration. Trump's family appeared first, drumming up the crowd with incendiary rhetoric. This is Donald Trump's Republican party! We are in this fight to the bitter end, we are going to take our country back! Reporter: At noon, the president took the stage, further fueling the fire of anger and dissent. We will never give up, we will never concede, it doesn't happen. You don't concede when there's theft involved. Reporter: He called on congress to reject the election results, an election he lost by 7 million votes but continues to call rigged, despite no evidence. We're going to walk down, any one you want, but I think right here, walk down to the capitol. You'll never take back our country with weakness. You have to show strength, and you have to be strong. Madam speaker, the vice president and the United States senate. Reporter: By 1:00, the much-anticipated joint session of congress got under way. When we got to the state of Arizona, a Republican member of congress named Paul Gosar stood up to object. Reporter: That objection forcing the house and senate to separate and debate. Over on the senate side, majority leader Mitch Mcconnell bluntly confronting his Republican colleagues. The voters, the courts, and the states have all spoken. If we overrule them, it would damage our republic forever. Reporter: As debate continued inside, outside, president trump's supporters arriving, and the mood distinctly changes. Stop the steal! Stop the steal! Reporter: Demonstrators soon climbing the walls and scaffolding, violently confronting law enforcement. It was clear that the crowd was intent on causing harm to our officers by deploying chemical irritants on police. Reporter: While inside, the vice president was whisked away by the secret service. They're breaking the windows! Reporter: As the mob moved in, the entire capitol went into lockdown, but protesters were already inside. Some carrying confederate flags. Law enforcement was no match for the sheer size of the invasion. Officers forced to retreat. In the house chamber, lawmakers huddled in the balcony as armed security barricaded the door. At one point, shots fired. A protester hit. She eventually dies. They brought out a woman on a stretcher, rushed her inside. We did see blood gushing. There's now smoke coming from over by the house gallery. Reporter: For hours while his supporters rampaged through the capitol, breaking onto the senate floor, into Nancy Pelosi's office, the president said nothing. By 4:00, President-Elect Biden publicly called on trump to stop the mob. I call on president trump to go on national television now to fulfill his oath and defend the constitution. And demand an end to this siege. Reporter: Just minutes later, trump released a video statement full of lies about the election. I know your pain. I know you're hurt. We had an election that was stolen from us. But you have to go home now. We have to have peace. So go home. We love you. You're very special. We love you, you are special. Those are the words of the president about the people that had just stormed the capitol building. So a very strange turn of events. Reporter: The video taken down from all social media sites as the president continues to refuse to condemn the actions of his supporters. This is on him. It's completely on him. On his broken psychology. Most grown-ups understand that you don't win them all, and at some point you have to learn to lose. Reporter: By 5:00, law enforcement starts reclaiming control of some parts of the capitol grounds. Multiple sources telling ABC news, president trump repeatedly refused to send in the national Guard before finally agreeing in the late afternoon. An hour later, a city-wide curfew goes into effect, with pamphl threats that demonstrators who don't leave will be arrested. Let's get back to work. Reporter: Despite the taken enall around, lawmakers took back the floor. United States senate will not be intimidated. We will begin the hard work of repairing this nation tonight, because here in America, we do hard things. In America, we always overcome our challenges. Reporter: Returning to work determined to finish the democratic process.
This transcript has been automatically generated and may not be 100% accurate.