Washington (CNN) A hearing in federal court over a potential impeachment witness Tuesday illustrated just how slow the courts can be -- hours after House Democrats highlighted the issue.

House Intelligence Chairman Adam Schiff, a California Democrat, had said earlier Tuesday the courts can take months to decide cases about witness testimony, and that's why the House hasn't used the courts more to resolve its standoffs with the White House.

Following more than an hour of arguments Tuesday afternoon, federal Judge Richard Leon didn't decide what to do with recalcitrant impeachment witness Charles Kupperman's court case, leaving major questions about congressional subpoena power and White House immunity during impeachment still far from a judicial resolution.

The House subpoenaed Kupperman, a former deputy national security adviser, in late October, and the White House told him not to testify. He went to court at that time, asking for the judge's intervention. He never testified, and the House withdrew his subpoena.

Throughout the hearing, Leon, a George W. Bush appointee with a sometimes unpredictable streak, repeated at least three times that the House "might not be in a hurry to have this court address the merits of this case."

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