Hours after the Senate voted against seeking new evidence in the impeachment case against President Donald Trump, the administration acknowledged in a midnight court filing Friday the existence of two dozen e-mails that reveal the president's thinking about withholding military aid to Ukraine.

The Department of Justice filed a response to a lawsuit seeking access to unredacted copies of those communications. Heather Walsh, a lawyer for the Office of Management and Budget (OMB), wrote to the court that 24 of those e-mails were protected under "presidential privilege."

"Specifically, the documents in this category are e-mails that reflect communications by either the President, the Vice President, or the President's immediate advisors regarding Presidential decision-making about the scope, duration, and purpose of the hold on military assistance to Ukraine," Walsh wrote.

The crux of the impeachment case against Trump is whether he used the $391 million in military aid to Ukraine and a coveted White House meeting for Ukrainian President Volodymyr Zelensky as leverage to force the foreign leader to conduct political investigations, including one focused on former Vice President Joe Biden. In a July 25 call, Trump had asked Zelensky to "do us a favor."

The Senate voted 51-49 on Friday to block witnesses and other new evidence, clearing the way for Trump's likely acquittal this week. Trump and administration officials had stonewalled the House impeachment probe, refusing to allow some witnesses to testify and to provide requested documents.

Why Trump wanted Congress-approved assistance to Ukraine delayed is the central question of his impeachment and was the greatest point of tension in the Senate trial.

Many of the witnesses who did testify in the House impeachment investigation hadn't been given an official reason.

William Taylor, the acting U.S. ambassador to Ukraine, recalled during his Oct. 22 deposition that he learned of the hold during a July 18 conference call, when an OMB aide said the security assistance was being held but couldn't say why.

"All that the OMB staff person said was that the directive had come from the president to the Chief of Staff to OMB," Taylor said. "In an instant, I realized that one of the key pillars of our strong support for Ukraine was threatened."

During the Senate trial, House Democratic managers argued there was sufficient evidence to conclude that the president was using the money as leverage to pressure the Ukrainian government to launch a public investigation into Biden and his son Hunter Biden.

But White House defense lawyers argued during the Senate trial that Democrats couldn't prove motive, and they suggested it was possible Trump had mixed motives in placing a hold on the aid, both personal and in the public interest.

The House managers said that was why they wanted the Senate to subpoena additional documents and witnesses with firsthand knowledge of the president's thinking, such as acting chief of staff Mick Mulvaney and former national security adviser John Bolton.

Rep. Adam Schiff, D-Calif., who led the House prosecution case, warned Friday that the contents of such e-mails will eventually be public.

"The facts will come out in all of their horror," Schiff said in closing remarks. "The documents the president is hiding will come out. The witnesses the president is concealing will tell their stories."