You can't have an Obama speech without some metaphors thrown in. Metaphors are symbolic comparisons between unlike things and often use strong imagery to create a poetic effect. Dig these examples:

• Comparing the state of the nation to a stormy sea (3.3)
• Describing America's values of equality as a "precious gift" to "carry forward" (7.5)
• "The long rugged path towards prosperity and freedom" (8.4)
• Calling for a "watchful eye" on the free market (15.3)
• Calling the era of segregation a "dark chapter" in history (21.3)
• Telling Americans to keep their "eyes fixed on the horizon" (32.3)

What's so effective about using metaphor in speeches? First of all, it sounds cool. Dropping some poetic language entertains audiences way more than rattling off statistics. Unless you're speaking at a statistics convention, we guess. Like, people fall in love with each other over metaphors (ahem, "shall I compare thee to a summer's day?").

Metaphor is also a great way to form a compelling narrative about a situation. Comparing the recession to a stormy sea creates a story in the audience's head, one about survival and perseverance in a scary situation. Aren't you kind of picturing an actual choppy ocean with a boat getting bounced around? Much of the president's job is to create narratives, either to get people on board with things ("trust me, this war is gonna be great") or to inspire the nation ("dust yourselves off, America").