Supreme Court Justice Sonia Sotomayor accused President Donald Trump's Department of Justice of asking the high court to "destroy the structure of government" by overturning 90 years of legal theory on who the president could fire.

During a hearing on Monday, Solicitor General John Sauer argued that a 90-year precedent on who the president can remove "must be overruled." The hearing comes after Trump tried to fire Rebecca Slaughter, a Federal Trade Commissioner appointed by Democrats.

"You're asking us to overturn a case that has been around for nearly 100 years, correct?" Sotomayor said of what's known as the Humphrey's Executor.

"90 years, I believe," Sauer agreed.

"What other cases have we overturned that have had a pedigree of 100 years?" the justice asked.

Sauer said there were 13 cases, but Sotomayor pressed: "But which other case has fundamentally altered the structure of government?"

"Aren't you asking us to distort it a different way?" she continued. "Neither the king, nor parliament, nor prime ministers, England at the time of the founding ever had a unqualified removal power."

"You're asking us to destroy the structure of government and to take away from Congress its ability to protect its idea that the government is better structured with some agencies that are independent," Sotomayor noted.

"Humphreys described this power as unrestricted and illimitable," Sauer insisted.

"You still haven't answered my question," Sotomayor said. "Where else have we so fundamentally altered the structure of government?"

"I think what the fundamental alteration of the structure of the government was ushered in by Humphreys," Sauer asserted, "and then the Congress kind of took Humphreys and ran with it in the building of the administrative state, in the proliferation of independent agencies that are insulated from democratic control."

"Independent agencies have been around since the founding," Sotomayor pointed out.