Here’s some free advice for Stephan Passalacqua and Jill Ravitch: “Trust me” isn’t a winning campaign slogan in 2010. It probably never was.

Politicians, used car salesmen, alas, journalists. None of us are on top of the polls when the question involves credibility. Yet the two candidates for Sonoma County district attorney seem to counting on voters to buy their campaign themes while holding back the fine print.

As my colleague Paul Payne reported Sunday, Passalacqua says Ravitch specializes in sweetheart deals for defense attorneys. Maybe he knows something. He was her boss, after all. But he’s refused entreaty after entreaty to back up his charge with some evidence. That’s what prosecutors do, right?

Ravitch has her own unexplained campaign themes. She and her surrogates, including Sheriff Bill Cogbill, say Passalacqua drags his feet on filing cases and is inconsistent about criminal charges. For example? They don’t want to get into that … just trust them.

Negative campaigning has its place. There are differences between candidates and elected officials, in style, philosophy, demeanor, goals. There’s no place, however, for spineless campaigning.

Here’s hoping Passalacqua and Ravitch are more forthcoming tonight when they debate at 7 p.m. at the Sonoma County Central Library in Santa Rosa.

— Jim Sweeney