The impeachment trial of former President Donald Trump which begins on Tuesday, February 8, is set to be an historic event in the politics of the United States as no president has ever been impeached twice or put on trial.

The trial is seen as an “undertaking like no other in US history” as the defeated former president is being charged with inciting the violent mob attack on the Capitol Building on January 6, to overturn the election in what prosecutors have argued was the “most grievous constitutional crime,” likened to a coup.

Trump’s lawyers have insisted that he is not guilty of the sole charge of “incitement of insurrection,” saying his words to the protesters were mere figures of speech, even as he encouraged a rally crowd to “fight like hell” for his presidency.

Trump, who is the first US president to face charges after leaving office and the first to be twice impeached for high crimes and misdemeanors while in office, has continued to challenge the nation’s civic norms and traditions even in defeat.

Security remains extremely tight at the Capitol as the Senators begin proceedings. And while acquittal is likely, the trial will test the US’s attitude toward Trump’s brand of presidential power, the Democrats’ resolve in pursuing him, and the loyalty of Trump’s Republican allies defending him.

Trump’s defenders are also preparing to challenge both the constitutionality of the trial and any suggestion that he was to blame for the insurrection. They suggest that Trump was simply exercising his First Amendment rights when he encouraged his supporters to protest at the Capitol, and they argue the Senate is not entitled to try Trump now that he has left office.

House impeachment managers, in their own filings, asserted that Trump had “betrayed the American people” and there is no valid excuse or defense.

His incitement of insurrection against the United States government, which disrupted the peaceful transfer of power, is the most grievous constitutional crime ever committed by a president,” the Democrats insisted.

With senators gathered as the court of impeachment, the trial will begin with a debate and vote on whether it is constitutionally permissible to prosecute the former president, an argument that could resonate with Republicans keen on voting to acquit Trump without being seen as condoning his behavior.

Under an agreement between Senate Majority Leader Chuck Schumer and Republican leader Mitch McConnell, the opening arguments would begin at noon on Wednesday, with up to 16 hours per side for presentations.

After that, there will be hours for deliberations, witnesses and closing arguments. The trial was set to break on Friday evening for the Jewish Sabbath, but Trump’s defense team, concerned about the delay, withdrew the request, and now the trial can continue into the weekend and next week.