US Supreme Court nominee Brett Kavanaugh speaks on the second day of his confirmation hearing in front of the US Senate on Capitol Hill in Washington DC, on September 5, 2018.

President Donald Trump's Supreme Court nominee Brett Kavanaugh on Wednesday sought to downplay Democratic concerns that he would issue rulings protecting the president from potential legal jeopardy.

During his second day of confirmation hearings before the Senate Judiciary Committee, Kavanaugh said that "no one is above the law," and called the landmark 1974 case forcing President Richard Nixon to turn over White House tapes "one of the greatest moments in American judicial history."

That case, which Kavanaugh said two decades ago may have been wrongly decided, ultimately led to Nixon's resignation from office.

Democrats have said that Kavanaugh could protect Trump from special counsel Robert Mueller as well as prosecutors in New York who are looking into the president's business and financial dealings.