reagan's shining city on a hill? >> there's nothing inevitable about american democracy. this is a fragile, fallible, complicated experiment. >> that experiment has faltered before. it's almost failed, only to return triumphant. to understand how that happened, we need to go back almost a century ago. >> it was an existential crisis. >> the early 1930s. the great depression is battering a nearly broken country. >> depression, fear and failure stalk the nation. >> the jobs are gone. farms are foreclosing. there are riots in the streets, fights over scraps of food. franklin delano roosevelt has just been elected.