A divided Senate voted on Tuesday to proceed with Donald J. Trump’s second impeachment trial, narrowly rejecting constitutional objections after House prosecutors opened their case with a harrowing 13-minute video capturing the deadly Capitol riot he stands accused of inciting.

Though the presentation stunned senators who lived through the rampage into silence, only six Republicans joined Democrats in clearing the way for the case to be heard. The 56-to-44 vote was the second indication in two weeks that Trump was all but certain to be acquitted.

“The result of this trial is preordained,” Senator Ted Cruz, Republican of Texas, said flatly. “President Trump will be acquitted.”

Even so, the nine House Democrats prosecuting the former President aimed their opening arguments squarely at Republicans who had the power to change the outcome. They cited an array of conservative legal scholars to argue that the Senate not only had the right to try a former President for official misconduct, but an obligation. And they offered a raw appeal from the well of the Senate, where a month before lawmakers had taken shelter as the pro-Trump mob closed in.

“Senators, this cannot be our future,” said Representative Jamie Raskin of Maryland, the lead manager, as he fought back tears. He described being locked inside the House chamber while colleagues called loved ones “to say goodbye” and his own daughter and son-in-law feared for their lives nearby.

“This cannot be the future of America,” he continued. “We cannot have Presidents inciting and mobilising mob violence against our government and our institutions because they refuse to accept the will of the people.”

It was a prelude to a case that Raskin and his team will begin prosecuting in full on Wednesday. They seek to prove that Trump spent his final months in office trying to overthrow the election, using baseless claims of widespread voter fraud to rally supporters in Washington and then encourage them to march to the Capitol to try to confront Congress as it met to formalise President-elect Joseph R. Biden Jr’s victory.

The House managers faced off against a hastily assembled legal team for Trump that offered an at-times meandering defence, before ultimately arguing that trying the former President would violate the Constitution.

It began with a circuitous presentation from Bruce L. Castor Jr, who complimented the compelling case made by the managers and then launched into a speech that appeared to confuse and bore some senators in both parties.

His partner David I. Schoen was sharper, asserting that Democrats were driven by an “insatiable lust” to destroy Trump. Schoen warned that they would instead damage the country by setting a new standard to pursue former officials, despite the fact that the House voted with bipartisan support to impeach Trump before he left office.

The House voted 232 to 197 to approve a single article of impeachment, accusing Trump of “inciting violence against the government of the United States” in his quest to overturn the election results. Ten Republicans joined the Democrats in voting to impeach him.

To convict Trump, the Senate would need a two-thirds majority to be in agreement. This means at least 17 Republican senators would have to vote with Senate Democrats to convict.

A conviction seems unlikely. Last month, only five Republicans in the Senate sided with Democrats in beating back a Republican attempt to dismiss the charges because Trump is no longer in office. On the eve of the trial’s start, only 28 senators say they are undecided about whether to convict Trump.

If the Senate convicts Trump, finding him guilty of “inciting violence against the government of the United States”, senators could then vote on whether to bar him from holding future office.

That vote would only require a simple majority, and if it came down to party lines, Democrats would prevail with Vice-President Kamala Harris casting the tie-breaking vote.

If the Senate does not convict Trump, the former President could be eligible to run for public office once again. Public opinion surveys show that he remains by far the most popular national figure in the Republican Party.

“Under their unsupportable constitutional theory, and tortured reading of the text, every civil officer who has served is at risk of impeachment if any given group elected to the House decides that what was thought to be important service to the country when they served now deserves to be cancelled,” Schoen said.

The defence’s case drew perplexed reactions from Republicans, evidently including Trump, who — barred from Twitter and out of sight in Florida — lacks the public megaphone he frequently used to weigh in on his first trial. The performance prompted at least one Republican, Senator Bill Cassidy of Louisiana, to side with Democrats on the vote to allow the trial to proceed.

“Anyone who listened to President Trump’s legal team saw they were unfocused, they attempted to avoid the issue and they talked about everything but the issue at hand,” said Cassidy, who had voted last month in favour of a constitutional objection to the trial and was the only Republican to switch his position on the matter on Tuesday. He quickly drew rebukes from the party.

The debate reflected the historic nature of the undertaking. Though in the 19th century the Senate agreed to try a war secretary after he left office, it has never before sat in judgment of a former President. Trump is also the first President ever to be impeached and stand trial twice, and certainly the only one to require a court of impeachment to meet in the middle of a deadly pandemic.

New York Times News Service