First:
Because the investigation has already uncovered criminal activity to which the perpetrators have pled guilty and/or been indicted! That pair of facts alone already have proven:
- There was wrongdoing committed by Trump Admin./Campaign personnel
- There were ideas expressed and actions undertaken about which Trump Admin./Campaign personnel felt obliged to lie.
Second:
Because the only ways to "fight back" against a criminal indictment are (1) lying, or (2) presenting a strong legal case that refutes the veracity of the prosecution's assertions, and that must be done in in a courtroom.
"Because the investigation has already uncovered criminal activity to which the perpetrators have pled guilty and/or been indicted!"
^^^^ Except that Michael Flynn has nothing to do with Russia, Michael Flynn is to do with Turkey. Paul Manafort has nothing to do with Russia, Paul Manafort is to do with Ukraine.
Are you being deliberately obtuse or do you not know that what is colloquially call the "Russia" investigation is in fact the whole of
the scope of the investigation Robert Mueller was emplaced to perform?
The Special Counsel is authorized to conduct the investigation confirmed by then-FBI Director James B. Corney in testimony before the House Permanent Select Committee on Intelligence on March 20, 2017, including:
- any links and/or coordination bet ween the Russian government and individuals associated with the campaign of President Donald Trump; and
- any matters that arose or may arise directly from the investigation; and
- any other matters within the scope of 28 C.F.R. § 600.4(a).
If the Special Counsel believes it is necessary and appropriate, the Special Counsel is authorized to prosecute federal crimes arising from the investigation of these matters.
I don't know what formal legal background you have, but, essentially, the scope statement of that order says
"Go see if there's any 'there, there' regarding the accusations we've heard about coordination between Trump's campaign team and the Russians. And if in the course of conducting that investigation, you find other crimes that appear to have been committed, investigate and, where there's enough evidence to obtain a conviction at trial, prosecute their perpetrators too."
Because that is the scope of the investigation, nothing pertaining to Russia need be found for the Special Counsel's investigation to have done what it has been tasked with doing.
While it's convenient to call Mueller's investigation the "Russia" investigation, the fact of the matter is that from its inception as an FBI investigation well before Mueller was appointed, its scope was to find criminal activity of any sort, not just criminal activity that involved Russia or Russian state actors/cutouts. Anyone who ignores that reality does so at the risk of showing their naivete.
Insofar as whether Mueller has already successfully identified criminal activity and obtained guilty pleas and indictments as instructed by the order that sat him, all the "fighting back" in the world cannot undo that. The question going forward is how much
more successful the investigation will be.