More importantly, presidential succession, in this case, depends on (to paraphrase former Sen. Howard Baker in reference to the Watergate Investigation) what the Vice President knew and when he knew it. Specifically, was the vice president aware during his September 1 conference with Zelensky in Poland, that Trump had previously asked for a “favor” when discussing military aid and that the favor included a Ukrainian criminal probe of Joe and Hunter Biden. The political futures of Mike Pence and Nancy Pelosi may well depend upon the answers to these questions.

If Pence’s September trip was intentionally designed to reinforce Trump’s demand for a “favor” with an intimidating follow-up message from the vice president, Pence may have a serious problem.

It could put him right in the thick of the impeachment soup as a co-conspirator with the president.