Not getting into the weeds on the issue of the day, BUT
House rules and Senate rules are two different creatures, institutionally and culturally. All 435 members of the House are elected every two years. The House reconstitutes itself and adopts its rules every two years. On the Senate side, however, only one third of Senators stand for election each cycle. Two thirds carry over. The Senate therefore regards itself as a continuing body whose rules, originally written by Thomas Jefferson, carry forward automatically without being readopted every two years. Over 200 years, this has given rise to a very different institutional culture surrounding the rules and potential changes to the rules. It is why, for example, the Senate typically proceeds by unanimous consent on procedural matters. That doesn't mean that Senate rules can't be changed. It does mean that there is no automatic, built-in point at the beginning of each session at which rules changes are in order. Mitch McConnell can't just snap his fingers and order up a new rule. The cultural barrier to rules changes is much higher in the Senate.
The Senate could change the rules,subpoena the witnesses but how to they physically force a witness to appear or answer any question?
“Mitch McConnell can’t just snap his fingers and order up a new rule. The cultural barrier to rules changes is much higher in the Senate.”
Well of course he can. If he wants a rules change he gets it with 50 Senators voting with him. Perhaps, maybe the cultural aspect of the Senate would prevent this but to say McConnell “cannot” is simply not true.
Thanks for your reasoned explanation of the difference in House and Senate rules. One other point is that the Speaker of the House is a Constitutional Officer elected by a majority of the House while the Senate Majority Leader is only a Party Official elected by the Majority Party.