> That one reads more like "all questions about their activities must be asked in the House and no where else",
Read literally, perhaps, but US courts have interpreted that clause more broadly to give general immunity to legislators for their legislative activities. For example, from Gravel v. US [0]:
> Rather, [Gravel's] insistence is that the Speech or Debate Clause, at the very least, protects him from criminal or civil liability and from questioning elsewhere than in the Senate, with respect to the events occurring at the subcommittee hearing at which the Pentagon Papers were introduced into the public record. To us this claim is incontrovertible.
> The Speech or Debate Clause was designed to assure a co-equal branch of the government wide freedom of speech, debate, and deliberation without intimidation or threats from the Executive Branch. It thus protects Members against prosecutions that directly impinge upon or threaten the legislative process. We have no doubt that Senator Gravel may not be made to answer either in terms of questions or in terms of defending himself from prosecution -- for the events that occurred at the subcommittee meeting.
Or from Eastland v. United States Servicemen's Fund [1] (citations omitted; there are a lot of them!):
> The question to be resolved is whether the actions of the petitioners fall within the "sphere of legitimate legislative activity." If they do, the petitioners "shall not be questioned in any other Place" about those activities, since the prohibitions of the Speech or Debate Clause are absolute[].
> Without exception, our cases have read the Speech or Debate Clause broadly to effectuate its purposes []. The purpose of the Clause is to insure that the legislative function the Constitution allocates to Congress may be performed independently.
> "The immunities of the Speech or Debate Clause were not written into the Constitution simply for the personal or private benefit of Members of Congress, but to protect the integrity of the legislative process by insuring the independence of individual legislators." []. In our system "the clause serves the additional function of reinforcing the separation of powers so deliberately established by the Founders." [].
> The Clause is a product of the English experience. []. Due to that heritage, our cases make it clear that the "central role" of the Clause is to "prevent intimidation of legislators by the Executive and accountability before a possibly hostile judiciary []," []. That role is not the sole function of the Clause, however, and English history does not totally define the reach of the Clause. Rather, it "must be interpreted in light of the American experience, and in the context of the American constitutional scheme of government...." []. Thus, we have long held that, when it applies, the Clause provides protection against civil as well as criminal actions, and against actions brought by private individuals as well as those initiated by the Executive Branch.
Entirely fair points that give weight to the thesis that Constitutions evolve by their lengthy interpretations over time ( "living documents subject to ammendment and interpretation" )
Bare bones, stand alone, Ye Olde clauses such as this are subject to a breadth of literal interpretation.
What did they "really" mean?
What do we want it to mean?
I count the modern US Supreme Court literalists as deceptives, hell bent on framing original clauses to extract the meaning they want in order to apply them how they wish.
That one reads more like "all questions about their activities must be asked in the House and no where else",
which is politically more like an open, transparent, on the record clause (no off the record Q&A's over What'sApp and Telegraph).
Elsewhere, in Commonwealth countries, they have https://en.wikipedia.org/wiki/Hansard recording all debates and questions.
Always fun transcoding the meaning of language over time.