Washington (CNN) A federal judge on Monday dismissed a lawsuit that former Trump national security official Charles Kupperman had filed challenging a House subpoena for him to testify in the impeachment inquiry after the chamber withdrew their subpoena.

Judge Richard Leon wrote in a 14-page opinion that there is no expectation that the House will reissue the subpoena, therefore the lawsuit is unnecessary.

Notably, by ruling the case is moot, Leon was able to sidestep the thorny issue of separation of powers and whether the White House could claim some administration witnesses have immunity.

Leon, however, noted that things can change in the future.

"Have no doubt though, should the winds of political fortune shift and the House were to reissue a subpoena to Dr. Kupperman, he will face the same conflicting directives that precipitated this suit. If so, he will undoubtedly be right back before this Court seeking a solution to a Constitutional dilemma that has long-standing political consequences: balancing Congress's well-established power to investigate with a President's need to have a small group of national security advisors who have some form of immunity from compelled Congressional testimony."

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