A federal judge tore into all of the legal arguments that a lawyer for US President Donald Trump's former campaign chairman Paul Manafort made on Wednesday in his long-shot civil case to convince her that Special Counsel Robert Mueller's investigation has run amok and should be reined in.
"I don't really understand what is left of your case," US District Court Judge Amy Berman Jackson said to Kevin Downing, Manafort's attorney, after peppering him with a lengthy series of questions.
Manafort filed a civil lawsuit on January 3 in the US District Court for the District of Columbia against Mueller and Deputy Attorney General Rod Rosenstein, the Justice Department official who appointed the special counsel, in a key legal test of how far Mueller's mandate extends.
Jackson did not say when she might rule on the civil case, which the Justice Department is seeking to dismiss.
Mueller is investigating possible collusion between Trump's campaign and Russia as well as whether the president has unlawfully tried to obstruct the probe.
Mueller has charged 22 individuals and entities to date, including Manafort and his associate Rick Gates. Manafort's civil case marks the first time a defendant has sought to challenge his authority.
Manafort, who performed lobbying work for a pro-Russian former Ukrainian president before serving as Trump's campaign chairman in 2016, is facing two indictments brought by Mueller in federal courts in Washington and Alexandria, Virginia. The charges against him include conspiring to launder money, failing to register as a foreign agent, bank fraud and filing false tax returns.
Manafort has pleaded not guilty and none of the charges directly relate to work he performed for Trump's campaign.
Trump has denied colluding with Russia and called Mueller's probe a witch hunt.
Manafort's civil lawsuit relies on an arcane law called the Administrative Procedure Act, which spells out the process federal agencies must follow when writing regulations. The suit alleges that Rosenstein's order laying out Mueller's investigative mandate violates Justice Department rules because it is overly broad and therefore "arbitrary and capricious."
Legal experts from the start have said Manafort's civil lawsuit faced an uphill battle.
The Justice Department's regulations explicitly say that private parties have no right to challenge them in court. Judges in prior cases also have generally not permitted defendants in criminal cases like Manafort to use civil litigation to try to challenge criminal charges.
