I think he was saying that there was a climate of negative campaigning, and not saying that only SA was doing it.
You want to see negative campaigning done by SA though? Just look at the comments on this blog and the anonymous personal attacks on Justin, who is technically a candidate.
Anyway I'm glad that Manassero followed his heart and mind, and not his party, in endorsing the CalSERVE executive slate, just as he did so in his courageous stances against the legal fees bill and against impeachment of Sonya Banerjee.