As the bad news keeps on coming in the San Mateo Union High School District, the need for strong, qualified, credible leadership becomes more paramount with each passing day. Superintendent Sam Johnson is out by the end of June. A majority of the trustees, the same folks who hired Johnson in the first place, finds itself with a less than scintillating track record. The big question on the immediate horizon is: Who will be the interim superintendent while the board members seek a permanent replacement for their lame duck top administrator? Their problem is that the district’s administrative bench isn’t just thin, it’s practically non-existent. Most, if not all, of the experienced people are long-gone. Who knows, the embattled board may have to find a way to yank someone out of retirement for several months. It’s a truly bad situation any way you care to slice it.