Diane Ravitch still hasn't figured this out about her friend Randi Weingarten.
Weingarten is an obvious mole, a fake, just like Barack Obama is a fake Democrat put in the party to weaken and eventually kill it. There is precedent for that sort of thing, so it isn't conspiracy nonsense. Infiltration of perceived opponents was done time and again during the 1960s-1970s with anti-war and other "left" groups seen as "subversive" by the FBI. What makes people think this sort of thing still isn't going on?
Neoliberals can't win on rational arguments, for what they believe is untenable in a democracy or even a functioning society, so they engage in various forms of subterfuge in order to "win." Infiltration of unions and political parties is one way to do it.