This song is in protest to what was formerly the Immigration and Naturalization Service (now part of the Department of Homeland Security) and their raids of undocumented immigrants in the United States. But instead of inciting violence, the song preaches peace between Americans and immigrants. "Migra" is slang in Spanish for the Immigration and Naturalization Service.

Structurally this is one of the simplest songs on the album. It consists of a verse over a bass riff, drum groove and a single chord with three contrasting interludes. These interludes add variety to what is otherwise a very repetitive structure. After all of these basic elements have been introduced they are repeated and layered together in different combinations.

Clave is the repeated rhythmic pattern used as the basis of Afro-Cuban music. There are two basic types of clave, Rhumba Clave and Son Clave. Migra uses the Son Clave. This type of rhythm became popular when it was introduced to America and was quickly adopted by Rock ‘n’ Roll musicians such as Buddy Holly and Bo Diddley. Bo Diddley used the rhythm so much that it became known as the ‘Bo Diddley Beat’. Santana’s use of the clave in Migra closely resembles the Bo Diddley Beat.

The tonality in this song is questionable. The entire song is based around a single chord of F. Since the 3rd of the chord is not present there is uncertainty as to whether the song is in F major or F minor. We call this tonal ambiguity. Overall though, there is a sense of F minor as the main tonality.

The instrumentation in this song consists of guitar, sleigh bells, keyboards, accordion, bass, drums, percussion, congas, trumpet and trombone.