When the chamber gaveled in, prayed and said the pledge on Friday, only 18 senators were in the chamber -- six of them Republicans. More flowed in as the proceedings began, but Senate Minority Leader Mitch McConnell was one of the last to arrive in the chamber at 12:12 p.m.

As Trump's lawyer Michael Van der Veen played footage showing Rep. Jamie Raskin, D-Md., objecting to the electoral college count in 2017, Raskin fiddled his thumbs. He seemed to notice the sound of his voice but didn’t look up at the screens immediately.

Republican senators appear much more alert compared to the past two days when the House impeachment managers presented their arguments. Many are taking notes and Sen. Rand Paul, R-Ky., has been particularly attentive today, seen chuckling several times, including when footage played showing Rep. Maxine Waters, D-Calif., challenging Electoral College results. He was also smiling and nodding as footage played of Democratic responses to protests over the summer.

On the other side of the chamber, some Democrats could be seen shaking their heads and whispering at times during the presentation. When Sen. Bernie Sanders, I-Vt., was mentioned in reference to the shooting of Rep. Steve Scalise, R-La., Sanders was seen fidgeting with the cuff of his shirt, leaned back in his chair and not taking notes.

After van der Veen finished his arguments, whispers broke out. Some Republican senators were nodding and giggling.

Reporters inside the Senate chamber noted that as David Schoen was talking, only three Republican seats were empty and almost all of senators were paying close attention. Sen. Bill Cassidy, R-La., continued to take notes, as he has throughout the trial.

When Schoen brought up what he alleged was manipulation of exhibits by House impeachment managers, lead House manager Raskin began scribbling in his notepad furiously.

-ABC News' Trish Turner

Trump attorney David Schoen argued there's a "dangerous double standard" being applied by Democrats, many of whom have sought to impeach Trump ever since, he said, they were angered by his election in 2016.

"That same hatred and anger has led House managers to ignore their own words and actions and set a dangerous double standard. The House managers spoke about rhetoric, about a constant drumbeat of heated language," Shoen said. "Though I'm sure everyone watching expected, we need to show you some of their own words."

He went on to play a series of video of notable Democrats, including Vice President Kamala Harris, House Speaker Nancy Pelosi and Sen. Elizabeth Warren, D-Mass., calling for supporters to "fight" -- in an effort to paint Trump's words at the Jan. 6 rally as normal political speech.

Celebrities Madonna and Johnny Depp also made appearances in the video exhibit from Trump's defense team for their criticisms of the former president with Madonna saying at a political event, "I have thought an awful lot about blowing up the White House."

David Schoen, a member of Trump's legal team, asserted that there was not enough evidence about the events of Jan. 6 for the trial to give necessary due process to the former president. Schoen included a video of Democratic House managers saying "reportedly" multiple times in their argument.

"'Reportedly' is not the standard in any American setting in which any semblance of due process is afforded an accused. 'Reportedly' isn't even 'here is some circumstantial evidence.' It is exactly as reliable 'as I googled this for you.' And if you are worried that you might ever be tried based on this type of evidence, don't be" Schoen said. "You get more due process than this when you fight a parking ticket. "

Schoen also accused House managers of having inaccurate information in their exhibits and evidence.

"Let me say this clearly: We have reason to believe the House managers manipulated evidence and selectively edited footage. If they did, and this were a court of law, they would face sanctions from the judge. I don't raise this issue lightly. Rather, it is a product of what we have found in just the limited time we have had since we first saw the evidence here, with you, this week," Schoen said. "We have reason to believe that the House managers created false representations of tweets and the lack of due process means there was no opportunity to review or verify the accuracy."

Trump defense attorney Michael van der Veen argued that if the Capitol attack was premeditated as some criminal complaints are alleging, Trump couldn't have incited it.

"The fact that the attacks were apparently premeditated, as alleged by the House managers, demonstrates the ludicrousness of the incitement allegation against the president," van der Veen said. "You can't incite what was already going to happen."

However, House impeachment managers argued Trump primed his supporters for violence for months with false claims of election fraud. They also argued Trump was aware of the violence underway at the Capitol while safe at the White House but was intentionally slow in his response.

After the Senate decided it will not call any witnesses, lead House manager Rep. Jamie Raskin, D-Md., was the first to speak during closing arguments. He reiterated the prosecution's case, calling for the conviction of Trump.

"It was suggested by defense counsel that Donald Trump's conduct during the attack, as described in Congresswoman Beutler's statement, is somehow not part of the Constitutional offense for which former President Trump has been charged," Raskin began. "I want to reject that falsehood and that fallacy immediately. After he knew that violence was underway at the Capitol, President Trump took actions that further incited the insurgents to be more inflamed and to take even more extreme, selective, and focused action against Vice President Mike Pence."

Raskin went on to use his time to describe Trump's months-long campaign to discredit the 2020 election results by spreading misinformation, which he argued laid the groundwork for deadly events of Jan. 6. He went on to claim that the former president assembled the mob, incited it and then sent it off to the Capitol during his speech. At every point, Trump sided with the insurrectionists rather than the Congress, Raskin said.

Once when the violence began, Raskin declared that Trump ignored the violence and further incited it by aiming the attacks on his own vice president.

"There has never been a greater betrayal by the president of the United States of his office, and of his oath to the Constitution."

Raskin then took a moment to suggest the GOP used "cancel culture" against one of its leaders, Rep. Liz Cheney, R-Wyo., who voted to impeach Trump in the House.

"Liz Cheney is a hero for standing up for the truth, and resisting this retaliatory cancel culture that she was subjected to."

Raskin emphasized his gratitude toward the Capitol Police, and finished his argument by saying convicting Trump is a vote for the "security of our democracy."

"They attacked this building, they disrupted the peaceful transfer of power, they injured and killed people, convinced that they were acting on his instructions, and with his approval, and protection," Raskin finished. "And while that happened, he further incited them, while failing to defend us. If that's not ground for conviction, if that's not a high crime and misdemeanor against the republic in the United States of America then nothing is. President Trump must be convicted for the safety and security of our democracy and our people."