Describe the speakers voice in "Legal Alien." Which lines best illustrate the speaker's voice?

Pat Mora is a Mexican-American poet, and "Legal Alien" is about the struggles that Mexican-Americans face. The poem is thus likely to be at least in part autobiographical, meaning that the speaker's voice and the poet's voice might be one and the same.
In terms of the tone of the voice, the repetition of the phrase "able to" in the first half of the poem perhaps suggests pride, whereas phrases in the second half of the poem, like "American but hyphenated" and "viewed by Mexicans as alien" suggest a sadness. Despite the ability of Mexican-Americans, like the poet, to straddle both cultures, they seem to be looked down upon for not being entirely of one culture or the other. As the speaker says, she is "an American to Mexicans, / a Mexican to Americans."
The speaker's tone is also perhaps somewhat sad, implied by the lines, "masking the discomfort of being prejudged." However, in the final lines of the poem, the repetition of the word "by," followed by the homophonic "Bi," suggests a tone of defiance. "Bi" is a prefix meaning two, so by finishing with this word, the speaker is perhaps closing the poem with the insistence that Mexican-Americans are not half, or less than, but are in fact twice, and more than.