This is gaining critical mass. This will have one of several possible outcomes:
1. Rmoney will comply, like Nixon complied -- smoking gun, calls for him to step aside, etc.
2. Rmoney will not comply, and this will slowly erode his numbers.
3. Rmoney will leak one return out -- the "modified limited hangout" -- and this will lead back to 1, above.
4. Rmoney will release returns and they won't show anything fatal.
I bet 3. 4 would be a real problem and would certainly show Rmoney to be a very clever guy.