On June 18, 2015, the United States Supreme Court held (in a 5:4 decision) that Texas couldn’t be forced to issue license plates with the confederate flag. You can read the entire decision at http://1.usa.gov/1JWTN0G.

License plate at issue in the case.
Justice Breyer, who authored the majority decision, explained– “When government speaks, it is not barred by the Free Speech Clause from determining the content of what it says.”