• Ketanji Brown Jackson swatted away Trump’s claim that a top advisor did not have to testify before Congress.
• Jackson is widely believed to be President Biden’s potential Supreme Court pick.
• Her 2019 opinion, which drew considerable attention at the time, will almost certainly become a focal point if she is nominated.

US Circuit Court Judge Ketanji Brown Jackson, who is viewed as President Joe Biden’s likely Supreme Court pick, once issued a 118-page opinion that torched the Trump administration for arguing that former White House counsel Don McGahn didn’t have to cooperate with Congress’ investigation.

“Stated simply, the primary takeaway from the past 250 years of recorded American history is that Presidents are not kings,” Jackson wrote in 2019. “Rather, in this land of liberty, it is indisputable that current and former employees of the White House work for the People of the United States, and that they take an oath to protect and defend the Constitution of the United States.”

The Trump White House had argued for months that McGhan did not have to testify before House lawmakers about Russian interference in the 2016 presidential election and Trump’s efforts to thwart special counsel Robert Mueller’s investigation. Trump even directed McGhan to not comply with a congressional subpoena, part of his administration’s near-complete refusal to accede to congressional oversight.

“Thus, DOJ’s present assertion that the absolute testimonial immunity that senior-level presidential aides possess is, ultimately, owned by the President, and can be invoked by the President to overcome the aides’ own will to testify, is a proposition that cannot be squared with core constitutional values, and for this reason alone, it cannot be sustained,” Jackson continued.

A former clerk to Justice Stephen Breyer, Jackson is widely viewed as Biden’s likely pick to replace Breyer, who is reportedly retiring at the end of the high court’s term. Biden previously vowed to name a Black woman to the court, which would make Jackson a historic selection and only the third Black person to become a Supreme Court justice.

Some Senate Republicans zeroed in on Jackson’s 2019 opinion during her Senate confirmation hearing in April 2021. Biden had nominated Jackson to rise from the federal DC court to DC appeals court, the latter of which is widely regarded as a stepping stone to the Supreme Court.

Sen. Thom Tillis, a Republican from North Carolina, tried to connect Jackson’s decision in the McGhan case to the then-growing interest in her serving on the Supreme Court, The Washington Post reported.

“I know very well what my obligations are, what my duties are, not to rule with partisan advantage in mind, not to tailor or craft my decisions in order to try to gain influence or do anything of the sort,” Jackson said in response.

McGahn’s court fight stretched on for months and outlasted Trump’s time in the White House. Last May, McGahn finally reached an agreement to appear, two years after the fight over his testimony began.