First, since the House already has more than enough evidence of impeachable conduct, these witnesses are not, strictly speaking, essential. Sure, it would be impactful to have multiple witnesses, but frankly, Trump does not even seem to be disputing the facts.
Second, at the Senate trial, the rule for evidence under one party’s control that is withheld or destroyed should be the same as the rule in any court setting: that that evidence is presumed to be unfavorable. Hence, the Senate sitting as jurors should be told that Kupperman’s testimony should be presumed to verify the bombshell testimony of witnesses like William B. Taylor Jr.
Third, Schiff’s strategy seems wise. Unless the House wants to lose all momentum, drag this out until 2020, and litigate up and down the federal courts, it is best to move on for now. “Litigation equals avoidable delay and isn’t needed any longer,” tweets constitutional scholar Laurence Tribe. “We have the evidence now to prove clearly impeachable offenses. On to public hearings!”
Nothing prevents the House from simultaneously litigating and pursuing impeachment. If the former is successful, the new evidence can be thrown into the hopper for the Senate trial.
Fourth, the average mid-ranking civil servant trapped between orders from the White House and a subpoena is quite different than a Cabinet-level official such as Secretary of State Mike Pompeo or Attorney General William P. Barr, who are witnesses to serious misconduct and choose to assist the president’s stonewalling campaign. Congress could exercise its power of “inherent contempt” and try to lock these guys up, but that seems unwieldy. A better solution would be to proceed to impeachment of those senior officials as Trump’s impeachment moves to the Senate.
Senior officials who know full well there is no “absolute immunity” and whose actions are themselves suspect should not be able to hide behind a phony privilege claim. Pompeo, by recalling former ambassador to Ukraine Marie Yovanovitch, was arguably acting in furtherance of the conspiracy to enlist Ukraine’s help in the election. Barr has been traveling the globe to solicit dirt on Biden. Acting chief of staff Mick Mulvaney allegedly held up funds for Ukraine for Trump’s political benefit. For those officials in Senate-confirmed positions, impeachment on their underlying conduct and on their refusal to show up for testimony should be on the table. Witnesses can take the Fifth, but that is not a realistic option if they want to remain in the administration.
In short, there must be a severe consequence for officials participating in a stonewall campaign. The most logical and easily available power at Congress’s disposal is the impeachment power. If nothing else, it should give future Cabinet officials pause before complying with a baseless claim of privilege that just so happens to conceal their own role in impeachable conduct.