One of the subtleties here is that Mueller (possibly at the insistence of Rosenstein, possibly not) referred the case to the federal prosecutor for the Southern District of New York. Mueller's mandate is the Russia election investigation, after all. The upshot of this is:
- If Trump fires the entire Special Counsel's office, it doesn't affect the other case
- Because the issue is related to Trump's campaign, Jeff Sessions is still recused from this investigation
- There are now three active investigations, if you include cooperation with the New York State government.
"Kitto daijoubu da yo." - Sakura Kinomoto