Tim Russell was a key aide to Scott Walker when Wisconsin’s governor was Milwaukee County executive. But Russell’s been damaged goods, politically speaking, since the Milwaukee County DA’s Office charged him with embezzling thousands from a program that hosted military appreciation days at the zoo. Damaged, that is, but not forgotten: An attorney working for Russell filed a motion earlier this year that included a damning letter written by a county prosecutor. The missive claimed Walker’s office stonewalled the John Doe investigation into misuse of public resources, even as Walker was professing his complete cooperation. Et tu, Brute?