A state flying a Confederate flag constitutes government speech. Artwork on display in state or federal museums likewise constitute government speech.
However, the very notion of “government speech” is relatively new within Constitutional law. Here are two examples:
In Johanns v. Livestock Marketing Association (2005) the Supreme Court ruled that the government had the right to use tax-payer money to promote beef consumption.
In Pleasant Grove City, Utah v. Summum (2009) the Supreme Court ruled that the government could, as an exercise of speech, accept a Ten Commandments statue as a gift to be erected on government property, even if it chooses to reject gifts from other religious groups. Ironically, there are other Supreme Court cases where Ten Commandments displays have been deemed unconstitutional :lol:
Both of these examples demonstrate the awkward situations that arise now that the Supreme Court recognizes governments as entities which enjoy the freedom of speech. I am not sure that the founding fathers envisioned the government itself as a beneficiary of freedom of speech. In my opinion, the First Amendment applies first and foremost to individuals and the press.