"Immediately after announcing Mueller’s appointment, Rosenstein further assuaged Senate Democrats, promising that Mueller would have no limits. Rosenstein then approved a FISA warrant application that alleged, apparently based on the Clinton-campaign-generated Steele dossier, that the FBI believed Trump campaign officials were complicit in Russia’s hacking conspiracy against the 2016 election. Subsequently, Rosenstein memorialized his authorization to Mueller to investigate 'allegations' of collusion — apparently without spelling out any collusion evidence and very likely relying on the Steele dossier."