The U.S. Supreme Court will hear a free speech case on Monday to decide whether Texas was wrong to reject a specialty license plate featuring the Confederate flag. The state's board for the motor vehicles department declined a proposal in 2011 from the Sons of Confederate Veterans over the display of the flag on a specialty plate, which the group argues is to commemorate Southern heritage. The case underscores how states can regulate private messaging on government license plates without violating free speech. States may generate revenue by allowing external groups to propose license plates that people may pay an additional fee to use on their vehicle. A ruling is expected by the end of June.