A wry attack on the Mexican clergy, showing them deserting Matamoras with their "treasures"--young women, wine, and other booty. In the lead ride a priest and a monk on horseback with a woman seated behind each of them. Not far behind follow two more horses with clerics and their women.
Matamoras was the Mexican town on the Rio Grande taken by American troops in May 1846, at the start of the Mexican War. The artist's characterization of the priests as "rulers" is a bit of anti-Catholic sarcasm, alluding to the power of the Church (closely allied to the wealthy landowners) in Mexican politics.