The Democratic-led House impeached Trump on Dec 18 on charges of abuse of power for asking Ukraine to investigate political rival Joe Biden and obstruction of Congress for blocking testimony and documents sought by lawmakers in their investigation.
With acquittal seemingly assured, the Democrats prosecuting US President Donald Trump in his impeachment trial urged the Senate on Monday to convict him to show no president is above the law while his legal team called the case against him politically motivated, reckless and baseless.
"I submit to you on behalf of the House of Representatives that your duty demands that you convict President Trump," Democratic Representative Jason Crow told the 100-member Republican-controlled Senate, which is due to vote on Wednesday on whether to remove Trump from office.
The trial's outcome will have a lasting effect "not only for this president but for all future presidents: whether or not the office of the presidency of the United States of America is above the law," Crow added.
Senators heard closing arguments in the trial by the Republican president's legal team and the seven Democratic House members serving as prosecutors.
"This was the first totally partisan presidential impeachment in our nation's history. And it should be our last," Trump lawyer Jay Sekulow told the Senate.
"What the House Democrats have done to this nation, to the Constitution, to the office of the president, to the president himself and to this body (the Senate) is outrageous. They have cheapened the awesome power of impeachment."
The Democratic-led House impeached Trump on Dec 18 on charges of abuse of power for asking Ukraine to investigate political rival Joe Biden and obstruction of Congress for blocking testimony and documents sought by lawmakers in their investigation. Trump has called the impeachment effort the attempted coup by Democrats.
Sekulow called the impeachment drive reckless, said neither of the charges brought against Trump represent an impeachable offence and accused Democrats of seeking to negate the 2016 election won by Trump and to subvert the will of the American people.
"The answer is elections, not impeachment," Sekulow said.
"The president has done nothing wrong," added White House Counsel Pat Cipollone. "We can, together, end the era of impeachment."
The Senate seems certain to acquit Trump. A two-thirds majority is required to remove the president. None of the 53 Senate Republicans has indicated support for conviction.
"Impeachment is an extraordinary remedy - a tool only to be used in rare instances of grave misconduct," Crow said. "But it is in the Constitution for a reason: in America, no one is above the law, even those elected president of the United States - and I would say especially those elected president of the United States."
Representative Adam Schiff, who heads the Democratic prosecution team, said that Trump, if left in office, would continue to seek foreign interference in the Nov. 3 election in which he is asking voters to give him four more years as president. Biden is a leading contender for the Democratic nomination to challenge Trump.
"A president free of accountability is a danger to the beating heart of our democracy," Schiff said.
The Senate voted on Friday not to hear any witnesses such as Trump's former national security adviser John Bolton, who in an unpublished book manuscript depicts Trump as playing a central role in pressuring Ukraine, despite Democratic demands and opinion polls showing most Americans wanted to hear from them. Only two Republicans, moderates Mitt Romney and Susan Collins, voted to hear witnesses.
When the closing arguments are complete, the senators will be able to make speeches on the matter until Wednesday, when a final vote is scheduled at 2100 GMT on whether Trump is guilty of the charges and should be removed. Several Republican senators have called Trump's actions wrong and inappropriate but not impeachable.
During the trial, Trump's lawyers offered an expansive view of presidential powers and argued that he could not be thrown out of office for abuse of power.
"The logical conclusion of this argument is that the president is the state, that his interests are the nation's interests, that his will is necessarily ours," Crow said.
"Allowing a president to get away with conduct based on this extreme view would render him above the law," Crow added.
Trump is only the third US president to be impeached.
The first contest in the state-by-state battle to determine the Democratic candidate who will challenge Trump was taking place on Monday in Iowa, a stern test for Biden as he seeks his party's nomination. Three senators are seeking the Democratic nomination: Bernie Sanders, Elizabeth Warren and Amy Klobuchar.
Trump was scheduled to deliver his annual State of the Union speech to Congress on Tuesday night.