In case you missed it, I have a piece on Lawfare with further analysis of former Vice President Pence’s Speech or Debate argument. To bottom line it: (1) I think it is very unlikely that Pence will be able to get the subpoena quashed in its entirety; (2) Pence has a reasonable chance of succeeding on the threshold question of whether he is protected by the Speech or Debate Clause at all: (3) if so, there are likely areas where a court would hold he is protected from questioning (e.g., his communications internal to Congress related to the performance of his role as president of the Senate); (4) for the most important communications at issue (namely Pence’s communications with former President Trump and others outside Congress who were attempting to influence how he would exercise his role during the Jan. 6 electoral vote count), the Speech or Debate question is a close one that could go either way; and (5) in any event, the Senate has the power here to waive Pence’s Speech or Debate privilege and/or demand that he testify before the Senate regarding these matters.
And if you want to hear even more about this subject (and given that you are the sort of person who reads Point of Order, I assume you do), you can listen to me and Eric Columbus on the Lawfare podcast with hosts Quinta Jurecic and Molly Reynolds.