From today's concurrence by Sixth Circuit Judge Amul Thapar and Eric Murphy in Moms for Liberty v. Wilson County Bd. of Ed. You can read the panel opinion by Judge Jane Stranch, which is also joined by the other two judges, here. But there's a lot of procedural detail in the panel opinion, so I thought I'd focus on the simpler concurrence, which represents the view of a majority of the panel members, and lays out the constitutional issues (and briefly explains the procedural ones at the end):
For parents, few things matter more than their children's education. But when a group of moms began voicing concerns to their local Tennessee school board, they discovered that their input wasn't welcome. They now challenge the set of policies that restricted the tone, content, and format of their remarks. While I agree with the majority that the moms are not entitled to a preliminary injunction, I write separately to emphasize the troubling nature of the Board's rules.
Start with the Board's policy of cutting off "abusive" comments. The Board offers no guidance to distinguish "abusive" comments from critical or insulting ones. That distinction matters because the First Amendment prevents the government from discriminating against a speaker based on her viewpoint—regardless of whether that view is offensive or polite. When the Board bars offensive remarks but not flattering ones, it necessarily picks and chooses between opposing perspectives. This act of selection arguably makes the abusive-speech restriction an "egregious form of content discrimination" that is "presumed to be unconstitutional."
Put another way, the Board can't implement the equivalent of a "happy-talk" requirement that forces speakers to make their remarks "grammatically palatable to the most squeamish among us." In a free society, after all, the listener—not the government—decides whether remarks are worthwhile. And the price of that freedom is often unkind, offensive, or insulting speech.