The House Judiciary Committee opened the next phase of the Trump impeachment inquiry Wednesday with testimony by experts on constitutional law and impeachment.

Professors Noah Feldman of Harvard Law School, Michael Gerhardt of North Carolina School of Law, Pamela S. Karlan of Stanford Law School and Jonathan Turley of George Washington University Law School were expected to give lawmakers perspective on whether President Trump's actions involving Ukraine rise to the level of impeachable offenses.

The Judiciary Committee is responsible for drafting articles of impeachment.

In prepared remarks, Feldman gives an explanation of what the constitutional framers had in mind when they provided a mechanism for removing a president from office.

Gerhardt will testify the framers were concerned "about the need to protect against a corrupt president was evident throughout the constitutional convention."

Karlan's prepared testimony talks about the framers' concerns an unscrupulous person could rig elections, thwarting the real will of the people.

And Turley, the only one of the witnesses summoned by Republicans and who testified during the impeachment of former President Bill Clinton, will warn against lowering the standard for impeachable offenses and testify about the historical record.