Less crude slang term that refers to ANY person who possesses the following qualities: Ignorant, Unintelligent, and Belligerent. In short: an Asshole or Asswipe.
Note: It is unfortunate that some of the people considered to be "Mondays" are born and raised in less then suitable environments, and therefore, can't be blamed for who they are. It is also important to note that the majority of a whole ethnic group was oppressed and forced into poor living conditions which intern causes the generalization of that whole ethnic group to be labeled as "Mondays".
Monday:" Mel Gibson sure is a Monday"
Mondays:" The KKK, NBPP, and every other Gang who creates hate and violence are a bunch of Mondays"