As an FYI, it *is* OK for a non-profit to be involved with politics, but only in approved ways. Example: it is OK for a non-profit to try to help educate voters on an issue. Additionally, OK for a non-profit to hold, say, a "meet the candidates" night. Big difference, too, between supporting a particular candidate and supporting a cause. OK, for example, for the cancer society, to advocate for more cancer research funding. Wouldn't be OK for cancer society to promote a particular candidate by name, even if that candidate was loudly for increased research funding. Subtle but key difference.
Trouble (legal trouble or just ill will within a group) often starts when school staff or district officials push the parent groups to endorse a bond levy or tax override vote. Has your group been in this position?