Two years before President Donald Trump nominated him to a seat on the Supreme Court, federal appeals courts Judge Brett Kavanaugh said he believes the legal precedent that allows for independent counsels to investigate government officials for federal crimes should be overturned.

Asked at a conservative event in 2016 to name a case that he believed should be overturned, Kavanaugh named Morrison v. Olson, a Supreme Court ruling upholding a 1978 law that creates a system for independent counsels to investigate and potentially prosecute government officials for federal crimes. The law had five-year sunset provisions and was allowed to expire in 1999, according to the Congressional Research Service.

"It's been effectively overruled, but I would put the final nail in," Kavanaugh said at an event for the conservative think tank American Enterprise Institute. CNN was the first to report the comments.

After the law expired, new regulations allowed for the appointment of "special counsels," but unlike independent counsels, special counsels answer to the U.S. attorney general.

The president's campaign is under investigation by a special counsel, Robert Mueller, as part of the ongoing federal probe into Russian interference in the 2016 U.S. election. The president has called the investigation a "witch hunt" and the White House has insisted that Trump could fire Mueller if he wanted to. The president has also asserted that he has the "absolute right" to pardon himself.

Kavanaugh's familiarity with special investigations dates back decades. As a young attorney, Kavanaugh worked for independent counsel Kenneth Starr and played a key role in a slew of investigations into President Bill Clinton.

Democratic lawmakers, who have attempted to advance measures in Congress to protect Mueller's probe, immediately pounced on reports of Kavanaugh's comments.

Senate Minority Leader Chuck Schumer, D-N.Y., called for Kavanaugh to recuse himself from anything related to the Russia investigation.

“Clearly, Judge Kavanaugh's judicial philosophy incorporates an almost monarchical view of executive power and accountability animated by a belief that our chief executive gets to play by a different set of rules. Judge Kavanaugh, particularly after this interview, needs to recuse himself from anything having to do with the Mueller probe,” he said.

Sen. Richard Blumenthal, D-Conn., said it was evident Trump's high court nominee believes “the president is above the law.”

Sen. Dick Durbin, D-Ill., said Kavanaugh must answer whether he would support the existing special counsel investigation into Russian meddling and the Trump campaign.

Last week, 12 Russian intelligence officers were indicted as part of the Mueller probe for hacking and stealing materials from Democratic political groups while communicating with an ally of the Trump campaign under the persona of the hacker "Guccifer."

Previously, 13 Russian nationals and three Russian companies were indicted on charges from the investigation. Several former Trump aides and advisers have plead guilty, and campaign chair Paul Manafort has also been indicted.