Manafort is an idiot for not making a deal with Mueller. His guilt is more than obvious. The only thing I can think of for his failing to make a deal is he thinks Trump will pardon him. Only a fool would pardon Manafort but we are talking about Trump here. And tax evasion by the rich is something Trump has no problem with.
Let's not forget that Manafort's involvement with dodgy Slavs and their money-flows long predates his involvement with Trump. He may worry less about the Kremlin than about people in Brighton Beach. By not flipping on Trump he sends a message to them - "I'm no squealer".
Manafort not flipping on Trump for immunity in the face of almost certain conviction is odd but he must have his reason(s). And whatever they are, they must be compelling. I highly doubt loyalty to Trump is among them.
I don't think we know what is going on here, but one thing that is absolutely clear is Stacyhs is right about this: "And whatever they [reasons for not flipping] are, they must be compelling. I highly doubt loyalty to Trump is among them.
Some possible reasons he isn't flipping:
1. Seeing if he can get lucky with the jury: High profile trials attract jurors with an agenda, and it is conceivable that a raging pro-Trumper could hang the jury.
2. Playing for a pardon. This is fraught with problems for Trump and Manafort. It obviously doesn't get Manafort out of jail since conviction on state charges seems likely after a pardon. For Trump, a Manafort pardon in the face of this kind of overwhelming evidence would cause some political problems for Trump and it might cause real problems for pro Trump Republicans in the midterm elections. It might also be part of a case for impeachment against Trump. Still Manafort has few options and Trump may not have a lot of options to prevent the truth of his Russian involvements from becoming public.
3. Fear of violent retribution: Manafort has been playing high stakes games with some seriously violent people for a long time. If they can figure out a way to threaten him or his family with violence to keep his mouth shut they probably will.
4. Friends in high places: Manafort has been a Republican political operative for a long time and there are probably a lot of Republicans that have gotten money from him. They might work with the president to pressure Manafort to keep his mouth shut.
5. Not enough damning evidence against Trump to make it worth while for the prosecution to offer him a deal: This seems like a real possibility to me. Is there stuff he knows that Gates doesn't? Maybe, but if that is so, it is not public knowledge what that is.
6. He's a delusional nut job. This seems unlikely but it is more likely than that he is hanging tough out of loyalty to Trump.
Questions for the pro-Trumpers participating in this thread:
1. If given the opportunity would you get on a Manafort jury and vote not guilty in the face of overwhelming evidence of guilt if you believed it would help protect Trump?
2. Do you see the prosecution of Manafort as part of a deep state effort to undermine Trump?
3. Do you think Manafort is being unfairly prosecuted?
4. Why do you think Manafort isn't flipping?