If the Trump admin is about to start prosecuting sex crimes and human trafficking, it would be of tremendous benefit to the Executive Office to encourage the Washington Elite to publicly admonish those who may be guilty of such criminal activity. If information were to then arise that certain high level partisan insiders were guilty of similar crimes, the Press, the Deep State, the entire Establishment would be gutted.
The accusations against Kavanaugh are also conveniently timed to distract from any other policy concerns the public might have towards the nominee... but that's a different theory.