Imagine getting this impossible assignment: write a poem that hundreds of millions of people will hear and read; make sure all of them can understand it; make it hopeful, but acknowledge the hardship America's undergone in recent years, and in not-so-recent ones; make it reasonably short. You've got, like, a month to work on it: go!

That was the daunting task poet Elizabeth Alexander, 48, was given just weeks before President Obama's inauguration on January 20, 2009. "It was mid-December when I found out, and I finished it beforehand," says Alexander. "I didn't want any drama."

She still faced an internal drama: how can a poet, someone who makes a career of talking to herself, write one of the most public poems in history? Alexander's answer was to do just what she always does. "My regular way of working is just keeping track of things, keeping notes, sometimes pulling the car over, sometimes spacing out in the middle of something else, just always having scraps of paper, anything," she says. "Then I see what's there, what starts to grow. Then I do the actual work of writing the poem. I just tried to stay cool. It certainly broke the record for drafts—maybe 350 pages."

Alexander, surprisingly tall (you wouldn't have known it seeing her behind the inauguration podium) and also surprisingly funny (given how serious her poems often are), had to struggle with voices in her head that most poets don't hear: "I had to think about ‘accessibility' and poetic integrity at the same time—there were certain kinds of poems that would not have been appropriate—but not second-guess so much."

The result was "Praise Song for the Day," which asks, "What if the mightiest word is love?" The poem pans across people from all walks of life and commends the struggle that led to Obama's election, "the figuring it out at the kitchen tables." "Praise Song" will appear in book form for the first time in Crave Radiance: New and Selected Poems, 1990–2010 from Graywolf, along with a handful of other new poems and a generous selection from Alexander's five previous collections that interweave the stories of the close connections within families with the larger and very troubled stories of African-Americans in America. Currently the African-American Studies department chair at Yale, Alexander was a fairly well-known poet before Obama's inauguration—her 2005 collection, American Sublime, was a finalist for the Pulitzer, but she's experienced a very un-poet-like ascent to prominence over the past two years, which she's found both incredible and unsettling. "I really wanted to use all the opportunities to stump and proselytize on behalf of the dear, neglected art [of poetry], but also on behalf of the other part of my work, which is African-American studies," she says. "I wanted to talk about the ways that culture is actually at the center of American culture."

Fame is a rare thing for a poet, but Alexander hasn't let it get in the way of her writing or her life: "When you do more things in public, the haters come out. I did sort of grow my thicker skin. I wouldn't have let that get in the way of writing, but there was a period where I didn't like having so many people in my head," she said.

Alexander comes from a political family—her father, Clifford Alexander Jr., was secretary of the army, and her brother Mark was an adviser on Obama's campaign and part of his transition team. She was born in New York, but grew up in Washington, D.C., and has actually known the Obamas for many years, since way before the presidency was even a glimmer in his, or anyone's, eye. Alexander taught at the University of Chicago from 1990 to 1997, the time Obama was also on the faculty. "We were Hyde Park neighbors," she says, "and in a situation like that, you soon meet the people who are your age, who care about some of the same things. That seems like another lifetime. It's wild."

Watching a friend work his way to the presidency has taught Alexander more than a few things about life and art. "What's really powerful," she says, "is that if we are ready, we can all do so much more. You never know when you might have to go for it and step through that window that's opening and be ready, bring your best game and just make it work. I think of that as being a particularly African-American philosophy about life—when there is so much denied opportunity, you have to keep ready and hopeful for when things change."