The main character yells "people don't drink the sand because they're thirsty, they drink it because they don't know the difference." Earlier, he requests a dozen dogwoods from Carmen's Flowers, after being informed that it is the state flower of Virginia by Mrs. Chapil, but they don't have any dogwoods so he sends a ham instead. He slams a pool cue down when another character insinuates that he might have been a history 
The main character yells "people don't drink the sand because they're thirsty, they drink it because they don't know the difference." Earlier, he requests a dozen dogwoods from Carmen's Flowers, after being informed that it is the state flower of Virginia by Mrs. Chapil, but they don't have any dogwoods so he sends a ham instead. He slams a pool cue down when another character insinuates that he might have been a history professor. More famously, he tells Bob Rumson to come at him with more than a burning flag and an ACLU membership card if he wants to engage in a character debate, but not to mess with Sydney Ellen Wade. Starring Michael J. Fox and Martin Sheen, FTP, name this 1995 movie that features Michael Douglas as the title character, President Andrew Shepherd.
The main character yells "people don't drink the sand because they're thirsty, they drink it because they don't know the difference."
The {American President} (prompt on Andrew Shepherd)