When y ou are investigated or sued, the general sequence is:
Complaint-Response-Reply.
The officials that sued/investigated Donald Trump and the Trump campaign have in effect acted to lay down a complaint but they are not of Congress and therefore Congress has no basis to demand a role in a reply because they did not appoint the Special Prosecutor.
Congress certainly has the authority to question Mueller but they have no standing to issue orders as to how the executive process unfolds unless they pass constitutional law allowing them to do so. Good luck with that.
Congress can launch their own investigation and Rep. Schiff has said numerous times that he has sufficient, abundant evidence to charge the President with crimes and to impeach him. Let him proceed if he is able.
Congress’s role at this point is to review, question, and report. They are not allowed to usurp the executive process.
The copy of the Mueller Report is being made available to Congress as it was demanded and the Executive Branch is obligated to provide a copy when requested. It will be redacted but in Congress, the Gang of Eight, they are allowed to review the unredacted report in a secure facility known as a SCIF.
Unless Mueller informs that his report has been altered, the only option available to Democrats in Congress is to bring forth the evidence they claim they have (e.g. Schiff) or to stand down.
It’s a conspiracy! Mueller and Rosenstein were in on it, too. How dare they draw conclusions inconsistent with our sacred narrative./s