Plausible deniability is a velvety layer of insulation between the people who carry out the acts and the person elected or appointed to take responsibility. By the time the denials, obfuscations, delays, hand-wiping, shoulder-shrugging and tied-hands miming is done, the guilty parties are gone and the trail is so convoluted that it becomes very difficult to
prove that the leader was anything more than ignorant of what went on. That feigned ignorance, in turn, provides lots of grist for righteous indignation about unauthorized overreach by lone rogue actors, partisan charges that the opposition is trying to muckrake and blah blah blah.
Political abstractions may be leaky, but they hold water long enough to get the job done.