The cartoon you are referring to shows three business men in front of the U.S. Founding Fathers. One of them, acting as a spokesperson, interpellates the writers of the Constitution by asking them to scratch the first words of the Constitution ("We, the people..") and replace them with the statement "We, the anonymous corporate donors, untraceable foreign contributors and assorted billionaires.." So, if the U.S. Constitution began as suggested by the cartoon, the Supreme Court would make decisions that favored corporations ("we, the anonymous corporate donors") over individuals ("we, the people"). Fortunately this is not the case, but, throughout its history, and depending upon the Chief Justice who has led it, the Supreme Court has sometimes been especially friendly to business.
These two men seated at the table represent the Irish , with top hat and vest, and German (smoking pipe and drinking german beer) inmigrants in the 1800s in the US. The cartoon refers to the 1882's Chinese Exclusion Act, which was the first American law preventing the inmigration of an specific ethnic/national group. This can be apreciated in the "New Declaration of indepence" at the back of the cartoon.
The legend in the bottom ("If the Yankee Congress can keep the yellow man out, what is to hinder them from calling us green and keeping us out too?") refers to the raising fear in Irish and German groups of facing the same fate of Chinese inmigrants. This let us know American attitude towards inmigrants who weren't seen as equals and were discrimitated for their origins and skin color.
