A Florida judge has dismissed the US justice department’s classified documents case against Donald Trump in a huge victory for the former president just days after a gunman attempted to assassinate him.

Judge Aileen Cannon granted Trump’s motion to dismiss the federal case on the basis that the justice department’s appointment of special prosecutor Jack Smith violates the Appointments Clause of the US Constitution.

Trump pleaded not guilty to several charges in the case over his handling of classified documents, including willful retention of national defence information.

Dozens of classified files were found in Trump’s Mar-a-Lago resort in Florida, including in a shower and storage room, after Trump left the White House in 2021.

“The Court is convinced that Special Counsel’s Smith’s prosecution of this action breaches two structural cornerstones of our constitutional scheme—the role of Congress in the appointment of constitutional officers, and the role of Congress in authorizing expenditures by law,” Judge Cannon concluded in her 93-page order.

The former president faced 40 felony counts over his alleged mishandling of classified documents.

Attorney General Merrick Garland appointed Mr Smith in 2022 to oversee two federal investigations into the former president.

Judge Cannon said in her ruling that this decisions applies to this case and not a second one overseen by Mr Smith over alleged efforts to overturn the 2020 election.

The former president’s lawyers did not make a similar request to dismiss that case.

The Trump-appointed Florida judge had recently indefinitely postponed the federal classified documents trial, saying there were significant questions over trial evidence.

Legal experts have debated the strengths and weakness of the two federal criminal cases brought by Mr Smith.

On Monday, Judge Cannon stepped in and said those details did not matter.

She held that the mere existence of special counsels – how they are appointed and how they are funded – violates the US Constitution.

Judge Cannon’s ruling cuts against the ruling of judges in other US courts that have dealt with these specially appointed prosecutors.

It draws from theories advanced by some conservative legal scholars and, most notably, by Supreme Court Justice Clarence Thomas in the top court’s recently decided presidential immunity case.

Her decision also comes as Republicans gather in Milwaukee, Wisconsin, for the Republican National Convention, where Trump will be officially named the party’s nominee for president later this week.

Mr Smith will be able to appeal Monday’s ruling and ask for a new judge to be assigned to the case. Depending on the outcome of that appeal, the losing party could then turn to the US Supreme Court.

He has yet to publicly comment on Judge Cannon’s ruling.

On Monday, Trump said on his social media site that the dismissal of the case “should be just the first step, followed quickly by the dismissal of ALL the Witch Hunts”.

“Let us come together to END all Weaponization of our Justice System, and Make America Great Again!”

In May, Trump was found guilty of falsifying business records in a New York hush-money case. He is due to be sentenced in September.

He has also been charged with four criminal counts, including conspiracy to defraud the US and conspiracy against the rights of citizens, in the 2020 election case.

Trump and some 18 other defendants are also accused of criminally conspiring to overturn his very narrow defeat in the state of Georgia in the 2020 election in a separate case.

He has denied any wrongdoing.

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