The day’s events unveiled at least one piece of significant new information about the president’s conduct and set the stage for impeachment hearings to come.

The testimony released so far tells a story of the hijacking of the policy process and the conditioning of U.S. policy on political favors to Donald Trump.

In recent weeks, House Democrats have intensified their investigation into President Trump’s contacts with Ukraine, subpoenaing documents from the executive branch and calling administration officials to...