Donald Trump's lawyers said on Friday Democrats had provided no evidence the former president incited last month's deadly US Capitol riot and had used his second impeachment trial to settle political scores. 

Trump is on trial in the US Senate on a charge of inciting the Jan. 6 insurrection by supporters who stormed the seat of Congress in Washington to stop lawmakers from certifying Democratic President Joe Biden's election victory, resulting in the deaths of five people, including a police officer.

Trump's lawyers argued that his remarks, including a fiery speech that day urging supporters to "fight like hell" to stop the certification, were protected by the First Amendment of the US Constitution, which ensures the right to free speech.

"To claim that the president in any way wished, desired or encouraged lawless or violent behavior is a preposterous and monstrous lie," said Michael van der Veen, one of Trump's lawyers.

"Clearly, there was no insurrection," attorney Bruce Castor told the Senate jurors.

Trump's defense team also portrayed the impeachment trial as little more than the result of a political witch hunt by Democrats who had been trying to get Trump for four years.

A final up-or-down vote to convict could come as soon as Saturday.

In arguments this week, Democratic members of the House of Representatives showed videos and shared tweets they said made clear Trump had set the stage for the violence by falsely claiming the election results were fraudulent and egging on his supporters with his rhetoric long before Jan. 6. They said he summoned the mob to Washington, gave the crowd its marching orders and did nothing to stop the violence as it played out on television. His one request to act peacefully did not absolve him, they said.

The Democrats are unlikely to gain a conviction, as few Republican senators have come out against Trump, who remains popular among Republican voters.

The Democratic-controlled House impeached Trump on Jan. 13. Conviction in the 100-member Senate requires a two-thirds majority, which means at least 17 Republicans would have to join Democrats.

If Trump is acquitted, the Senate could decide to censure him or even vote to bar him from holding public office again. Asked on Thursday about pursuing the latter option, Senate Majority Leader Chuck Schumer said that decision would have to wait until the end of the trial.

Senator John Thune, the No. 2 Republican in the chamber, indicated that a censure motion could be in the cards.

Trump is the first US president to be impeached twice and the first to face trial after leaving office. His first impeachment trial, which stemmed from his efforts to pressure Ukraine to investigate Biden, ended in an acquittal a year ago in what was then a Republican-controlled Senate.