He wasn't arrested because he voiced his concerns, he was arrested because he violated the rules of the public proceeding. I don't know of any elected officials who can be commanded by a member of the public to read passages of a book out loud at a public meeting.
It is illegal to arrest someone for merely breaking the rules of a meeting. They have to actually commit a crime. Here he was arrested for disorderly conduct. However, violating the rules in the manner he did as described in the article (I've read no others yet and am assuming it is a true account), does not constitute disorderly conduct. Plus, they apparently created specific rules just for him. Thus, it is logical to conclude that the arrest (and special rules leading up to the arrest which had the effect of limiting his ability to express his concerns and inquire about the boards' reasoning), was designed to censor him. That is unconstitutional.
I get that there are political extremists that can make teaching and running school districts very difficult. I don't see this (from the article I read), as a political extremist or right or left issue. It's about the first amendment and the right to parent ones child and challenge those in power. In fact, it's one of the few cases recently that actually is about the first amendment (ahem, Donald Sterling, Benham twins, ahem, NOT about "free speech").
We simply cannot allow our government to censor us this way.
Some of you seem to feel it's okay because the father may be an extreme right winger. Well, that's not justification for removing his constitutional right to speech and parenting his child.
Just change the facts a bit. Here in SoCal recently we had a school board issue an assignment asking kids to read "credible" sources representing "both sides of the debate" as to whether the Holocaust actually took place. The question was: "Did the Holocaust really happen or was it a 'merely a political scheme created to influence public emotion and gain wealth.'"
If a parent had challenged the Rialto school district here in California over that assignment in the exact manner this man did, would you support the special rules and his arrest?
IMO we have to fight to protect the constitutional rights of every American to be free from government censorship of our speech, even the rights of those whose message we disagree with. If we don't, it will be our message that is censored next.