How does Li-Young Lee use imagery in For a Citizen of These United States?

Lee intertwines the simple language with powerful imagery throughout this poem, with probably the most compelling metaphorical imagery occurring in line 32. "But birds, as you say, fly forward" is a very straightforward, common sense piece of information, but its significance lies in what it represents rather than what it literally means. It is arguably the most important line in the poem and is clear evidence of Lee's ability to speak in plain English and still startle the reader with remarkable revelation.