The Preamble to the U.S. Constitution is old-timey and contains words and phrases like "tranquility" and "ordain to establish." But it's probably the most important part of the entire document.

The Preamble is to the Constitution what Shmoop summaries are to fusty history textbooks. It details the fundamental purposes of the document, as well as the most important parts: the people of the United States made the Constitution and therefore are protected under it; these same people give the document its power, which gives the country its power; the Constitution is designed to protect the people from a tyrannical government.

In his "A More Perfect Union" speech, Obama built on these basic principles that define the United States. He said that we the people give power to our government, not the other way around. We're the ones driving this bus, which means we have to choose between listening to Siri when she tells you to turn left into the woods or trust that we're on the right path, no matter what the GPS says.

Obama used the Preamble to illustrate that we have it backward. Our government doesn't get to decide on a "right time" to talk about race and inequality. We the people choose the time, and the place. But he also said we have to choose to talk about the right things, and that is half the battle.

Thirsty for more? Check out "Symbols, Motifs, and Rhetorical Devices" for more information on the Constitution.