Is There A Win Total That Saves DA’s Job?

I understand what you’re saying, but I disagree. There are only 32 openings for this job. I also would say you can walk in to the job and know you’re safe for a few years to build your team and dismantle this hot mess we are currently in.
There might be 32 but we won't be the only team looking if we go that route. I think he should go, but the way it happens needs to be professional. Firing him after one year would not make anyone think they're secure in the job, but keeping him on could be worse for the organization.