Unlike other impeachable officials, such as federal judges and executive-branch officers, the president and vice president are elected by, and accountable to, the people. The executive is also a coequal branch of government. Thus any attempt to remove the president by impeachment creates unique risks to democracy not present in any other impeachment context. Adhering to constitutional text, tradition and basic procedural guarantees of fairness is critical. These processes are indispensable bulwarks against abuse of the impeachment power, designed to preserve the separation of powers by preventing Congress from improperly removing an elected president.

House Democrats have discarded the Constitution, tradition and basic fairness merely because they hate Mr. Trump. Because the House has not properly begun impeachment proceedings, the president has no obligation to cooperate. The courts also should not enforce any purportedly impeachment-related document requests from the House. (A federal district judge held Friday that the Judiciary Committee is engaged in an impeachment inquiry and therefore must see grand-jury materials from special counsel Robert Mueller’s investigation, but that ruling will likely be overturned on appeal.) And the House cannot cure this problem simply by voting on articles of impeachment at the end of a flawed process.

The Senate’s power—and obligation—to “try all impeachments” presupposes that the House has followed a proper impeachment process and that it has assembled a reliable evidentiary basis to support its accusations. The House has conspicuously failed to do so.