Greg Campbell has been a legislative staffer for more than 20 years, and his current gig is at the top of the heap – chief of staff to Assembly Speaker John Pérez. The youthful Campbell knows the terrain — he’s about 40 and looks younger – and has worked in various leadership capacities through four speakerships and has become an institutional part of the Assembly’s power structure. The chief of staff is part political operative, part employee manager, part soother of the caucus and part communications strategist, characteristics that have to be coupled with solid social skills. It also helps to have a crystal ball: Having a sense when dormant issues are ready to draw public attention is indispensable. He’s back on the job after recuperating from major surgery. Gov. Brown had called and asked if there was anything he could do. Ever the political staffer, Campbell said yes, sign the speaker’s bill to expand Medi-Cal coverage. “I’m doing great because I have health insurance,” he told the governor.