from The Discovery of Poetry:
The Public Voice
When the speaker is "we," the poet presumes to speak for himself [sic] and others. "We" can be intimate, but usually "we" indicates that the poet will be concerned with a cultural or historical subject with broad scope and conclusions. The U.S. Constitution begins, "We the people..." and "we" intends to represent all citizens. A poem that uses this kind of "we" is a public voice poem. The public voice speaks for a group of believers or participants in a common situation. The poet therefore wants a larger platform than a personal voice would offer. The choice of "we" stakes out a different territory than "I." Twentieth-century poets are less willing to venture to speak from the broad, homogeneous religious and political viewpoints that poets of earlier times took for granted. The plurality of our culture makes "we" a difficult choice.
for the record... my WE is [usually] plurality.