Andres Mario Ramirez Cuevas is a partner, together with Alejandro Magallanes and Leonel Sagahon, in the mexican graphic design studio La machina del tiempo. He is internationally less well known than the other two, because, as Alejandro explained "he prefers to make posters for the streets, and not for the big competitions and yearbooks". Here are some recent political posters from his blog Musica contra el poder (Music against power):

The Virgin of Guadalupe, mexican icon, is wearing the mask of the Zapatistas

Andres Ramirez is incredibly productive, making a poster almost every day, 300 a year. You can find many of his posters all over Mexico City. Indeed, when I checked my digital poster archive for pictures of street posters that I took in 2004, I spotted the following examples:

The entrance of a music hall that is plastered with concert posters and pictures (Ramirez at lower right)