Ditto that. I worked on a campaign for a school board election, and there were voters who insisted on knowing the party affiliation of the candidates, even though it was a "non-partisan" election.
Also, once in office (any office), those "non-partisan" Dem/Communists start working their way up the ladder to bigger things where they can do more damage.
At our first school board elections (mid 90s), the ‘Dem endorsed’ candidates workers all showed up and slapped big “Teacher Endorsed” stickers on their yard signs at the polling places. Note it didn’t say “Teacher UNION Endorsed.” Made my blood boil.
And, you bet the School Board is a stepping stone on a political career. Even Marion Barry started on the DC School Board (you wonder why their schools rank 51st in the country?)