This is a Senate Investigation (inquiry), NOT a criminal investigation.
The Senate can investigate, gather documents and facts and that's it. After their so called investigation, they can vote to make a referral to the DOJ for a criminal investigation.
The Senate and The House have both made several referrals to the DOJ, both Sessions and Barr, in the past and both Sessions and Barr have refused to do anything about it.
Sessions stated on several occasions that "We do NOT go after our political opponents".
Also the DOJ (Barr) and the FBI (Wray) have refused to hand over documents requested by both the House and the Senate in the past, this will be more of the same.
The Senate will request documents, Barr will say "no" and the Senate will say "OK let's do lunch".
So sorry, but publically referencing referrals or turning over documents to the House or the Senate equals LEAKS you Fool.
