Ken Starr says a special prosecutor should not exceed his original mandate
I believe this is the place where the Deltas start coughing and muttering "bullshit" and "blowjob" under their breath, and not just because Starr is saying "do as I say, not as I do."
Here is the actual declaration:
"The Special Counsel is authorized to conduct the investigation, including:
(i) any links and/or coordination between the Russian government and individuals associated with the campaign of President Donald Trump; and
(ii) any matters that arose or may arise directly from the investigation"
As far as I can tell, Mueller has stayed within those boundaries. Any financial dealing (a link) between Trump (obviously an individual associated with the campaign) and the Russian government is specifically covered by the first part. That IS Mueller's specific charge, without even having to resort to the broad strokes of the second part of the order.
Here is a comparison of the Starr and Mueller investigations.