In recent weeks, some Democrats have struggled to cite a crime committed by President Trump in the Ukraine affair. While the Intelligence Community inspector general suggested the president might have violated campaign finance laws, Democrats have generally not specified what law or laws Trump might have broken — instead pointing out that, beyond treason and bribery, the Constitution does not list particular offenses that qualify for removal from office. The House has wide discretion in deciding what conduct, criminal or not, is impeachable.

Now, however, Democrats appear to be testing a new charge: The president committed extortion.