Though it's really hard to overcome Gavin's continued unwillingness to retract his endorsement-- I think doing so requires enough of everyone else to sign on to make it clear that he's alone (or close to it).
Has anyone tried authoring an open letter to Gavin, requesting that he makes a revised statement? And then members of the community could sign it. I'd imagine we'd get quite a few signatories. That would be a start, at least.