[1.] The First Amendment generally protects remarks on a wide range of matters, not just on politics, science, or other big subjects. As the Court held in U.S. v. Stevens (2010), "[m]ost of what we say to one another lacks 'religious, political, scientific, educational, journalistic, historical, or artistic value' …, but it is still sheltered from Government regulation." Or, to quote another case, Connick v. Myers (1983),
[T]he First Amendment does not protect speech and assembly only to the extent it can be characterized as political… We in no sense suggest that speech on private matters falls into one of the narrow and well-defined classes of expression which carries so little social value, such as obscenity, that the State can prohibit and punish such expression by all persons in its jurisdiction.
[2.] Nonetheless, the Court has at times held that speech on matters of purely private concern is less protected by the First Amendment, in certain contexts, than speech on matters of public concern. The Court so held in Connick (despite the quote above) as to government employee speech cases: Government employees have some First Amendment protection from being fired for speech on matters of public concern, but "when a public employee speaks … upon matters only of personal interest, absent the most unusual circumstances, a federal court is not the appropriate forum in which to review the wisdom of a personnel decision taken by a public agency allegedly in reaction to the employee's behavior."
