This was not the case with Gates. To the contrary, by Mueller’s own account, Gates had committed known, serious, readily provable offenses. Applying the manual passage that Kerr himself quotes, it cannot be said that unless Mueller declined to prosecute (or at least dropped the serious charges), “other means of obtaining the desired cooperation [were] unavailable.” Mueller could have demanded an appropriate plea and pressured Gates to earn sentencing leniency by cooperating (which is standard operating procedure); or he could have convicted him at trial and pressured him to cooperate in exchange for a reduced sentence (the usual alternative to the standard procedure).
In addition, while Gates’s cooperation in the prosecution of Manafort (and in the Russia investigation generally) is doubtless welcome, it is presumably unnecessary. The fact that Mueller indicted Gates and Manafort necessarily means the special counsel has a good-faith belief that his evidence is strong enough to persuade a rational jury to convict both of them. And in this instance, the narrative style of the indictment conveys the prosecutor’s assessment that the proof of guilt is quite strong. So, not only is time not of the essence here. Gates is not of the essence. Mueller was fully prepared to prosecute Manafort without any help from Gates. Putting Manafort aside, if Gates has other information relevant to Russia’s interference in the 2016 election (as the New York Times intriguingly intimated this week), neither Gates, Russia, nor President Trump is going anywhere.