Diego Rivera was always entirely on the side of the poor, and wanted his art to promote their cause and lead to real change. In the example of Night of the Poor, we see a large number of figures in the foreground asleep, though living in cramped and uncomfortable conditions. A number of children are found in this group, perhaps as a means to highlight the vulnerability of this group. Their clothing is simple and entirely in keeping with their social status which was entirely about survival at that time. They huddle by a doorway and on the other side we find a heavy contrast, with soldiers deep in discussion. There are also suited individuals at the back who could represent businessmen or perhaps government officials, but they are presented in a negative manner and clearly pose a threat to the sleeping residents closer to the bottom of the painting. A banner scroll hangs above the doorway and this gives the title of the piece, in the artist's native language.
The artist was clearly fond of using this topic within his work and around a decade later would actually produce a series of drawings which focused entirely on the huddle of figures found within this painting. This fresco dates from 1928, with the drawing coming about in the 1930s. He would also put together the sister piece, Night of the Rich, which continued his commentary on life in Mexico as he saw it, and the specific inequalities which were present at the time and may still be so today. Some experts have examined the piece in front of us here and drawn comparisons to how sleep is used within more traditional art, such as from the Italian Renaissance. Rivera would sometimes call upon such influences as a means to taking advantage of pre-conceived ideas but extend them to Mexican content and did so effectively a number of times. Giotto would use some of these themes within his work, for example, and we do know that Rivera came across his work whilst in Europe.
Rivera completed a number of large projects in which he would be commissioned to roll out a number of murals together within the same building. He would plan these items in great detail, normally drawing out the different elements prior to starting the main piece and this was also necessary in order to get approval for his designs. He liked to complete everything himself and so some of these murals could take many months to complete, though he was well paid for his service and also appreciated the content that he was asked to create. These works helped to establish him as a key figure within Mexico, not just an internationally respected artist, but also someone who loved the people of his nation, and also would regularly speak out on their behalf when many others would not.