I think that the letter writer who posted in a county newspaper on October 15th may have confused a proposal from Merrick Garland regarding School Board harassment.
There have been well financed campaigns to go after school Board members and election workers. These people have been followed, phoned and frightened with threats against them and their families. There is nothing innocent about these actions. I see no reason not to call what they are doing, "Terrorism."
I agree that School boards do need to hear from parents, but not with threats and intimidation.
To my knowledge "Critical Race Theory" is being taught as a college level course in some universities. I seriously doubt if it is being taught in any elementary school anywhere. My guess is that the people complaining about it, don't have the slightest idea what is being taught or who is teaching it.
The Newspaper letter writer evidently needs to know that Antifa isn't an organization, it is an idea. Conflating it with Black Lives Matter will confuse some people. BLM was formed as a social movement to protest racially motivated instances of police brutality. The violence in Portland was not instigated by BLM, but by other groups, like The Proud Boys and Patriot Prayer.
Lastly, the letter writer advocated Education vouchers. I personally believe in our public education system and I do not desire to have my public tax money going to support someone else's private school.