House Democrats have struggled to define Trump’s alleged offense. Initially, they described it as “quid pro quo.” Then they employed the term “bribery.” The legally correct designation is “self-dealing.”
Self-dealing is betraying your employer’s interests to enrich yourself. It’s a violation of the fiduciary duty of loyalty.
"We can assume the president might benefit from a Ukrainian investigation, but that doesn’t mean asking for an investigation was self-dealing as defined by fiduciary, and therefore by impeachment, law. There’s nothing unusual or improper about a president asking a recipient of U.S. foreign aid to address corruption. As for seeking political advantage: If we punished every politician who did that, they would all be swinging from the yardarm."
(Rob Natelson is senior fellow in Constitutional Jurisprudence at the Independence Institute in Denver, a constitutional historian, and a former constitutional law professor. He is the author of “The Original Constitution: What It Actually Said and Meant”)
https://www.theepochtimes.com/what-the-expert-panel-should-have-told-you-about-impeachment-but-didnt_3166413.html
Two of the three democrat witnesses before Nadler's committee had no expertise in impeachment law and had published no scholarly work. Only Truley, the republican witness and a leading authority on impeachment submitted a heavily footnoted written statement before his testimony.