I am not a lawyer, but would like to see a question to catch whether a candidate works for or on behalf of a political party, PAC, politician, or is some kind of hireling (or necessary sponsor) of one. But it seems doubtful whether everyone so affiliated would be forthcoming about that, particularly if they've signed an NDA (non-disclosure agreement). Therefore we might ask candidates a meta-question like:
"Are you now, and will you be, free from, and not under any obligations public or private, open or confidential, legal, occupational, or contractual, that motivate you to become a moderator, or which would otherwise alter your behavior as a moderator, and enjoin you from ever directly mentioning your participation in them?"
A "no" answer would be bad, and a sincere "yes" answer would be good. The idea being that while NDA's might forbid telling others about the NDA, they cannot prevent people who haven't signed one from telling us they haven't, nor prevent those who did sign one from saying that they haven't not signed one.