Donald Trump’s defence team has accused Democrats of exploiting the chaos and trauma of the US Capitol riots for their own political gain.

On the eve of the impeachment trial, his lawyers filed a 75-page legal brief in a last-ditch effort to defend the speech that the former President delivered to his supporters just before they attacked the Capitol.

Lawyers Bruce Castor and David Schoen have argued the Senate does not have the right to vote to impeach Mr Trump because he is no longer in office.

The pair maintain that his infamous January 6 speech was protected by the First Amendment and that Mr Trump did not call for any violence.

They argue Mr Trump’s references to fighting were metaphorical.

The lawyers blasted the impeachment case against him as an act of “political theatre”.

“This was only ever a selfish attempt by Democratic leadership in the House to prey upon the feelings of horror and confusion that fell upon all Americans across the entire political spectrum upon seeing the destruction at the Capitol on January 6 by a few hundred people,” the lawyers wrote.

“Instead of acting to heal the nation, or at the very least focusing on prosecuting the lawbreakers who stormed the Capitol, the Speaker of the House and her allies have tried to callously harness the chaos of the moment for their own political gain.”

It’s expected they will persist with those same arguments on the Senate floor.

Conviction unlikely

With Mr Trump now gone from the presidency, Republicans have shown little appetite for backing an impeachment conviction.

To stop him from seeking office in the future, at least 17 Republicans would need to pull off what pundits say is a near-impossible feat.

That is to break ranks and vote to impeach the former US president, who is charged with sparking an insurrection at the Capitol by calling on people to “fight” the results of the November 3 election he lost.

Mr Trump’s second impeachment trial starts at about 4am on Wednesday (Australian time), making for the first post-presidential impeachment trial in US history.

His defenders in the Senate have rallied around him, dismissing the action as a waste of time, and arguing his fiery speech before the US Capitol attack doesn’t make him responsible.

Five people, including a police officer, died during the insurrection.

Last month, 45 of the 51 Republican senators voted against holding an impeachment trial.

The vote suggested the near impossibility in reaching a conviction in a Senate where Democrats hold 50 seats but a two-thirds vote – or 67 senators – would be needed.

Photographers take pictures of the article of impeachment against President Donald Trump prior to it being signed at the US Capitol. Photo: Getty

Even CNN has projected Mr Trump will be acquitted by the Senate – for the second time.

But the trial won’t be without drama as nine Democrats – acting as the House impeachment managers – and the former president’s attorneys go head-to-head on the Senate floor.

One thing’s for sure; the Senate trial will be unprecedented.

• To read his lawyers’ first response to the article of impeachment, click here

Here’s what you can expect

Mr Trump’s second impeachment trial will be different from the first, in which he was charged with abusing his presidential powers and obstructing Congress by pressuring Ukraine to investigate his political opponents.

After House speaker Nancy Pelosi announced an impeachment inquiry on September 24, 2019, it took almost three months for Democrats to unveil the two articles of impeachment against Mr Trump, as details of his pressure tactics on Ukraine leaked out over the course of weeks.

It took another 48 days for a majority of the Senate to vote to acquit him, even with Senate business grinding to a complete halt as more than a dozen witnesses were called.

This time around, a single charge citing his role in the January 6 insurrection was brought forward just one week after millions of Americans watched in real-time his fiery speech at a ‘Save America Rally’ on TV and the subsequent events that unfolded.

Private citizen: Mr Trump’s lawyers argue the trial is unconstitutional. Photo: Getty

The trial is expected to last one, maybe two weeks, as the charges are considered much simpler to convey and understand.

Although Lawyer Mr Schoen, a devout Orthodox Jew, requested that the trial be suspended during the Sabbath – from Friday until Sunday (local time) – both sides hope to avoid a drawn-out trial.

Democratic Senators want to be able to pass President Joe Biden’s $1.9 trillion COVID stimulus plan and there are still well over a dozen of his Cabinet members who require Senate approval – all of which have been delayed until the trial is finished.

Republicans, on the other hand, don’t want the public to remain fixated on the actions that led to his demise.

Therefore unlike the first impeachment trial in which each side had 24 hours to make their presentations, Mr Trump’s defence team and the impeachment managers would have up to 16 hours to present their cases.

There would also be the option for both sides to debate if any witnesses should be called.

Not only would a conviction bar him from running for future office, but it would strip him of his post-presidential entitlements such as an annual, lifetime pension of about $US200,000 ($259,757).

Tweet from @SpeakerPelosi

The impeachment managers are expected to present extended video footage and photos of the attack in the hopes that it would remind Republicans of the horror of that day and sway them to vote to impeach Mr Trump.

A second impeachment acquittal by the Senate would be a victory for Trump – and prove he retains considerable sway over his party.

Still, it may not be the end of attempts to hold him accountable. A censure resolution has already been floated in the event he is not convicted.

-with AAP