Charles Kupperman, a former deputy national security adviser, sued in October after being subpoenaed by House Democrats to testify in their impeachment investigation into Trump's interactions with Ukraine. He had asked a judge to decide whether he had to comply with that subpoena from Congress or with a conflicting directive from the White House that he not testify.
Both the House of Representatives, which withdrew the subpoena, and the Justice Department, which had said it would not prosecute Kupperman for failing to appear before Congress, had asked the court to dismiss the case as moot.
U.S. District Judge Richard Leon agreed Monday in throwing out the case. He noted that the House had not only withdrawn the subpoena for Kupperman but had also stated explicitly that it would not reissue one for him. The judge also pointed out that Democrats had not mentioned Kupperman by name in an impeachment article they approved this month that accused Trump of obstructing Congress and its investigation.
“This conduct is of course entirely consistent with the repeated representations that counsel for the House has made to this Court," Leon wrote. “The House clearly has no intention of pursuing Kupperman, and his claims are thus moot."
The lawsuit was closely watched since it was a rare challenge of a congressional subpoena in the impeachment inquiry and because of the potential implications it carried for another witness whose testimony had been sought by Democrats: former national security adviser John Bolton.
Kupperman and Bolton have the same lawyer. As a senior adviser to the president on matters of national security, Bolton would have had similar arguments available to him had he been subpoenaed. Bolton had indicated through his lawyer that he would not testify in the impeachment inquiry without a subpoena, and he did not receive one from the House.
Senate Democrats have identified Bolton as among the current and former Trump administration officials they would like to hear from in a trial. Charles Cooper, a lawyer for Bolton and Kupperman, did not immediately respond to messages seeking comment.
Though Leon said he did not need to resolve Kupperman's case now, he acknowledged that the conflict could potentially resurface. “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,” Leon wrote.
“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," the judge added.
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