WASHINGTON (NYTIMES) - US President Donald Trump suffered multiple legal setbacks in three key swing states on Friday (Nov 13), choking off many of his last-ditch efforts to use the courts to delay or block President-elect Joe Biden's victory.

In quick succession, Mr Trump was handed defeats in Pennsylvania, Arizona and Michigan, where a state judge in Detroit rejected an unusual Republican attempt to halt the certification of the vote in Wayne County pending an audit of the count.

The legal losses came as Mr Biden was declared the victor in Georgia and a day after an agency in the president's own Department of Homeland Security flatly contradicted him by declaring that the election "was the most secure in American history" and that "there is no evidence" any voting systems malfunctioned.

On Friday, 16 federal prosecutors who had been assigned to monitor the election also directly debunked claims of widespread fraud, saying in a letter to Attorney General William Barr that there was no evidence of substantial irregularities.

In his first public remarks of the week, Mr Trump ignored the developments during an appearance in the Rose Garden. But he showed a momentary crack in his previously relentless insistence that he would eventually be proclaimed the winner of the campaign, saying at one point, "Whatever happens in the future, who knows, which administration, I guess time will tell."

Mr Trump's bad day at the bar began at dawn when news emerged that lawyers from the Ohio-based law firm Porter Wright Morris & Arthur had abruptly withdrawn from a federal lawsuit they had filed only days earlier on his behalf in Pennsylvania.

The firm's withdrawal followed internal tensions at the firm about its work for Mr Trump and concerns by some lawyers that Porter Wright was being used to undercut the integrity of the electoral process.

Then, shortly after noon, a lawyer for the Trump campaign effectively dropped its so-called Sharpiegate lawsuit in Arizona. That lawsuit had claimed that some ballots cast for Mr Trump were invalidated after voters in Maricopa County had used Sharpie pens, causing "ink bleeds."

The lawyer, Kory Langhofer, acknowledged that not enough presidential votes were at stake in the case to affect the outcome of the race.