You are just backing into the reasoning as all dems are. The goal is to impeach Trump and then back into some reasoning as to why that needs to be done. Whether he pleads the fifth or not does not matter. You will just move on to the next rationale.
Also, even though you and your ilk do not want to hear it, Trump is actually making major progress- with the help of the IG and investigative reporters- in regard to exposing Mueller's actions - which were set in motion by a corrupt Obama intel network- as a witch hunt. At some point, he may/will just declare "game over- I am not participating in anything/anymore, do what you have to do." And if he pleads the fifth and executive privilege as part of following through with that- don't be surprised if lots of people understand that and dont assume that he is guilty just because he does not walk into a trap. But then as discussed. The next move will be for Mueller, and people will be asking him to put on his case - because he must have a case even without trump's testimony, right? So let's see how that little fiasco works out too. The question then becomes "why are we impeaching someone on charges when the government can't even put on a case? Oh, I see, because just pleading the fifth in a witch hunt is an impeachable offense? Sure, okay, better make sure you win the senate for that type of argument.
And apparently you missed the substantial earlier discussion about how/whether Mueller can even get him into a position where he would have to plead the fifth without indicting him or attempting to indict him. Easy for you to do, not so easy for Mueller. Mueller's easy days are behind him unless he wants to just stick with picking off side players on bullshit charges. The pussy can't do the big kill. How many times have I had to point this out.
