I dunno why you're talking about "most criminal prosecutions" now, after you brought up the specific case of Thomas Drake (of which almost all charges were dropped). You can only move the goalposts so far before it gets annoying (especially since the parent post is talking about full on conspiracy-level "secret courts").
In any case, the plea bargain is 100% based on what the defense and the prosecution believe that a Jury would rule. It all comes down to the jury at the end. If neither side can agree on the plea bargain terms, then it comes down to the jury.
> Thomas Drake was able to escape the prosecutors also playing judge because he was able to afford representation, and his funds outlasted the pressure the prosecution was able to bring against him.
Do you think Edward Snowden won't have funds to afford representation? Or that the ACLU will fail to raise funds for this highly anticipated case?