The real-life case against the boy appeared to be rock solid. But it had to be referred to the highest court, in Sweden, which ultimately overruled the school's exclusion order.
Now researcher Kennert Orlenius of Skovde university, has found that around two-thirds of heads and three-quarters of trainee teachers backed the school.
About three-quarters of the 130 surveyed said they would also object to teachers with Nazi sympathies, even if they did not try to influence pupils.
The minority who opposed exclusion felt such a ban was itself a threat to democracy, an infringement of the boy's civil rights and a lost chance to influence him.
"Teachers and heads should be aware of different attitudes to democracy and be critical and reflective about the concept, " Kennert Orlenius told the EERA conference.
"The school must be an arena where students have freedom and opportunity to express their attitudes and notions."
"The meaning of democracy in school. What can democracy put up with according to trainee teachers and headteachers in Sweden?" By Kennert Orlenius, Skovde University, Sweden