Democrats put the blame for the deadly January 6 siege on the US Capitol squarely on Donald Trump on Wednesday, describing him as the “inciter-in-chief” and accusing him of the “worst violation of the presidential oath” in American history.

As the impeachment trial of the former US president kicked off in earnest, Jamie Raskin, the Democratic congressman leading the prosecution, zeroed in on Trump’s failure to halt the riot that left five people dead.

Raskin said the evidence showed Trump “completely abdicated his duty as commander-in-chief to stop the violence and protect the government and protect our officers and protect our people”.

To support his argument, Raskin pointed to social media posts and video clips posted by Trump during and after the violence, including a tweet that appeared to justify the riot: “These are the things and events that happen when a sacred landslide election victory is so unceremoniously & viciously stripped away from great patriots.”

Raskin also played a video posted by Trump while marauders were still raiding the Capitol, in which he told the rioters: “We love you. You’re very special. Go home.”

The congressman from Maryland said the evidence would show Trump “clearly incited” the insurrection that interrupted the certification of Joe Biden’s presidential election victory.

Shortly before the Capitol assault on January 6, the president told crowds on the National Mall: “If you don’t fight like hell, you’re not going to have a country any more.”

Impeachment managers — Democratic lawmakers who are acting as de facto prosecutors — have two full days to make opening arguments in Trump’s Senate impeachment trial. Trump’s legal team will be given equal time for their defence.

Raskin and his team alleged on Wednesday that the former president laid the ground for the riot during the election campaign, when he repeatedly claimed that the only way he could lose was if his opponents engaged in massive voter fraud.

“He truly made his base believe that the only way he could lose was if the election was rigged,” said Joaquin Castro, the Texas congressman who is one of the impeachment managers. “All of us know and all of us understand how dangerous that is for our country.”

Managers also detailed how Trump sought to overthrow the results of November’s presidential contest by “pressuring and threatening election officials” and launching dozens of failed court challenges.

Madeleine Dean, the congresswoman from Pennsylvania, focused on Trump’s efforts to reverse the outcome in Georgia, including a now infamous phone call between the then president and Brad Raffensperger, Georgia’s Republican secretary of state.

Trump asked Raffensperger to “find” the tens of thousands of votes needed for him to win there and separately called him an “enemy of the people”.

“Let that sink in,” Dean said. “A Republican public servant doing his job, whose family had just received death threats, and the president of the United States labelled him an enemy of the people.”

US media on Wednesday reported that Fani Willis, the recently-elected Democratic prosecutor in Fulton county, Georgia, had opened a criminal investigation into Trump’s efforts to overturn the election results there.

A person close to Raffensperger confirmed the secretary of state had received a letter from the prosecutor regarding the matter. The prosecutor’s office did not respond to a request for comment.

Democrats are hoping they can persuade Republicans that Trump should be convicted for inciting an insurrection and barred from holding future office.

But it remains highly unlikely that the former president will be convicted. Under the US constitution, two-thirds of the Senate — which is split 50-50 between Democrats and Republicans — needs to find Trump guilty in order for him to be convicted.

Trump is the first president in US history to be impeached twice, and the only former president to face trial. He was impeached, or charged, by the House of Representatives in a bipartisan vote last month, just a week before Biden was sworn in. Ten Republican House members joined all House Democrats in that vote.

Trump’s trial started on Tuesday with a four-hour debate on whether it was constitutional to try a former president. But 44 of 50 Republicans sought to throw out the trial in the vote, signalling their loyalty to the former president.

Impeachment managers on Tuesday played a 13-minute video that included graphic scenes of violence at the Capitol. They were on Wednesday expected to present more footage, including previously unseen images from inside the legislative complex.