Sen. Sheldon Whitehouse, a member of the Senate Judiciary Committee, requested information from Supreme Court Justice Samuel Alito tied to an interview with The Wall Street Journal last year in which the justice questioned whether Congress has the power to impose ethics rules on the Supreme Court.

In the letter made public on Friday, Whitehouse, D-R.I., accused the conservative justice of offering “an improper opinion regarding a question that might come before the Court” amid an ethical…