Democrats appear to have fallen short in their bid to garner the votes needed to call witnesses in President Donald Trump's impeachment trial, clearing the way for his likely acquittal as early as this weekend.
In the final days of the trial, the Democrats worked to get at least four Republicans to support the effort, but their hopes appeared dashed when Republican senator Lamar Alexander, who had been undecided, declared further evidence in the case was unnecessary.
Barring an unforeseen change of heart by another Republican senator, it appeared Senator Alexander's decision would bring a swifter conclusion to Mr Trump's two-week trial.
Democrats needed at least 51 votes to call witnesses to prolong the trial.
Late on Thursday, Republican senator Lisa Murkowski said, "I am going to go reflect on what I have heard, reread my notes and decide whether I need to hear more."
A 50-50 tie on the question of witness testimony and additional evidence could result if Ms Murkowski and senator Mitt Romney join Republican senator Susan Collins in backing the additional evidence.
Such a deadlock would mean that the drive for witnesses would fail, unless US Supreme Court Chief Justice John Roberts, who is presiding over the Senate trial, voted to break the tie.
The backing of two-thirds of the Senate is required to remove Mr Trump.
However, he is unlikely to be convicted.
Democrats had hoped to hear from former national security adviser John Bolton after a report — which he did not deny — said he planned to write in an upcoming book that Mr Trump told him he wanted to freeze $US391 million ($581 million) in US military aid for Ukraine until it investigated Democratic presidential contender Joe Biden and his son Hunter, who worked for a Ukrainian energy firm while his father was vice-president.
The Democratic-controlled House of Representatives impeached Mr Trump in December, formally accusing him of abusing his power for pressuring Ukraine to investigate the Bidens.
The House also charged Mr Trump with obstruction of Congress.
Mr Trump's acquittal would allow him to claim vindication just as the Democratic Party holds its first nominating contest for the November 3 election in Iowa on Monday.
On Friday, each side is expected to present closing arguments before the Senate moves to the question of whether to call witnesses.
While Friday's session could run late into the night, one senior Senate Republican aide said the vote on Mr Trump's acquittal could be engineered to take place during daytime hours on Saturday or even Monday.
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ABC/Reuters
