Two comments.
First, to say he "violates" the Constitution is to just another case of hyperbole to make what Trump said seem "criminal." But the purpose of the Clause you cited is to keep Schiff, in this case, immune from prosecution. It "arguably" doesn't prevent the executive or the judicial from necessarily making comments like Trump did. In fact, we see comments being made all the time; they're just phrased in a more clever, more ambiguous way so that one could get away with making them without accusations being made against the comment maker. Think "passive-aggressive." But another reason folks are getting their knickers in a twist is that it's Trump making the comments (yet again another case of #OrangemanBad). Do the same (or similar) rules apply to this idiot group of Congresspersons?
Second, speaking of "arguably" the CRS doc you posted via the FAS link makes the point:
My sense is that Schiff's asinine comments while "reading" the transcript (later stated by Schiff to be "parody") do not clearly fall under the category of "legislative act" in that he read something demonstrably false into the congressional record without stating at the time he was making a parody reading. Again, my sense (not being a lawyer, but someone trying to wind my way through the arcane world of "parliamentary procedure") is that Schiff opened himself up to legitimate criticism by doing what he did. Or are you saying that Schiff does, in fact, get "supercitizen" status?
Schiff wants folks to believe his immunity is absolute. It isn't. Bottom line, my sense is that Schiff's comments were outside the protections of this Clause and thus were fair game by the Executive.
Finally, a comment regarding how this thread (and many others) evolved. Yes, the back and forth here on the forum (and just about anywhere) are filled with silly comments. So if you want serious discussion post a serious thread. To start off the way you did invites "return fire" (not saying a serious well-thought out post won't get "return fire," but one can only control what one does...).
This is a shame because far too often potential great threads are ruined by an initial post that begs the question in a too apparently partisan manner. Rarely does a thread start with a thoughtful question or a well-stated position; more often than not the thread is started/written as a taunt. One forum member comes immediately to mind: posts interesting subjects used solely as a means to flog and provide an excuse to engage in ad hominem. It ain't limited to this supposedly right-leaning forum; the same takes place - unfortunately - EVERYWHERE. Sure, some folks see "middle school food fighting" as fun, but then we wonder why it's so hard for us citizens to have civil discussion these days?
--- End of line (MCP)