Miami, Florida - Donald Trump faltered in a first attempt to have federal charges of mishandling classified documents dismissed as a federal judge partially ruled against him Thursday.

Trump was present in a Miami courtroom as lawyers tried to convince District Judge Aileen Cannon that she should toss out charges of unlawfully retaining national defense information, conspiracy to obstruct justice, and making false statements.

The ex-president is accused of taking top-secret material and improperly storing it at his Mar-a-Lago estate in Florida after his time in office. Prosecutors also allege that he repeatedly and intentionally frustrated efforts to recover them.

On Thursday, Trump's legal team argued that the Espionage Act that forms the basis of the indictment is too vague and that it should be struck down on constitutional grounds.

Donald Trump Panama president rules out talks with Trump over canal threat: "There's nothing to talk about"

That was a bridge too far for Cannon – appointed as judge by the Republican in 2020 – who said it would be an "extraordinary step" for her to essentially invalidate a major federal law.

She did not, however, definitively rule on a second challenge from Trump's lawyers, who insisted that under the Presidential Records Act, he was entitled to take the documents with him as his own personal property.

Cannon indicated throughout the hearing that at least some of the issues raised by defense attorneys would be best decided on by a jury – a strong sign that she intends to let the trial proceed.

A date has not been set, and further delays have become a major political flashpoint, with Trump expected to face Joe Biden in the 2024 presidential election.