WASHINGTON (Reuters) - Even with acquittal seemingly assured, Democrats prosecuting President Donald Trump in his impeachment trial made a forceful appeal for conviction on Monday, calling him a man with no moral compass who must be removed to protect American democracy.

U.S. Representative Adam Schiff wrapped up closing arguments for the seven House of Representatives impeachment managers after Trump’s lawyers called the case against the Republican president politically motivated, reckless and baseless.

“We have proven Donald Trump guilty. Now do impartial justice and convict him,” Schiff told the 100-member Senate.

“He has betrayed our national security and he will do so again. He has compromised our elections and he will do so again. You will not change him. You cannot constrain him,” Schiff said. “If you find the courage to stand up to him, to speak the awful truth to his rank falsehood, your place will be among the Davids who took on Goliath - if only you will say, ‘Enough.’”

The impeachment drama neared its conclusion a day before Trump is due to give his annual State of the Union speech to Congress. In Iowa on Monday, voters participated in the first contest in the state-by-state process of choosing the Democratic nominee to challenge Trump in the Nov. 3 election.

On Wednesday, the Republican-controlled Senate is set to vote on whether to remove Trump from office. It looked more certain to acquit him after Senator Lisa Murkowski, a Republican moderate, said in a speech Monday evening that she would not vote to convict despite calling Trump’s actions “shameful and wrong.”

Senator Joe Manchin, a Democratic moderate, said he had not decided on whether to vote to acquit Trump and saw “no path” to the two-thirds majority needed to remove a president. But Manchin predicted that a bipartisan majority in the Senate would vote to censure Trump for his actions, a lesser rebuke.

None of the 53 Senate Republicans has called for conviction.

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 in the investigation. Trump has called the impeachment effort an attempted coup by Democrats.

Trump personal lawyer Jay Sekulow urged senators to “stand firm.”

“This was the first totally partisan presidential impeachment in our nation’s history. And it should be our last,” Sekulow said. “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.”

Schiff said America’s founders intended impeachment - the power given to Congress under the U.S. Constitution to remove a president for committing “high crimes and misdemeanors” - to be used rarely.

But he said it must be used to remove a president who “would sell out his country for a political favor,” undermine the integrity of elections and invite foreign interference in American affairs.

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‘THE ANSWER IS ELECTIONS’

Sekulow said neither charge brought against Trump represented an impeachable offense, and accused Democrats of seeking to negate the 2016 election and subvert the will of the American people.

“The answer is elections, not impeachment,” Sekulow said.

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“The president has done nothing wrong,” White House Counsel Pat Cipollone added. “We can, together, end the era of impeachment.”

During the trial, Trump’s lawyers offered an expansive view of presidential powers and argued he could not be removed for abuse of power. Seizing on these arguments, Schiff told the Senate that if a president cannot be impeached for abuse of power, that would open the door to a range of “utterly unacceptable conduct.”

“Trump could offer Alaska to the Russians in exchange for support in the next election, or decide to move to Mar-a-Lago (his Florida resort) permanently and let (son-in-law) Jared Kushner run the country, delegating to him the decision whether to go to war,” Schiff said.

Schiff said Trump, if left in office, would continue to invite foreign interference in November’s election, in which he is seeking re-election. Biden is a leading contender for the Democratic nomination.

“What are the odds if left in office that he will continue trying to cheat? I will tell you: 100 percent,” Schiff said.

“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 from any witnesses, including Trump’s former national security adviser John Bolton, who in an unpublished book depicts Trump as playing a central role in pressuring Ukraine. Only two Republicans, moderates Mitt Romney and Susan Collins, voted to hear witnesses.

Senators will be making speeches on the matter until Wednesday, when a vote on whether Trump is guilty is scheduled at 4 p.m. EST (2100 GMT).

Trump is only the third U.S. president to be impeached. No president has ever been removed from office through impeachment. President Richard Nixon resigned in 1974 before the full House could impeach him.