What is the main point the cartoonist is making in this cartoon?

The main idea of this cartoon is that money plays too important a role in American elections. The donkey (a symbol of the Democratic Party) and the elephant (a symbol of the Republican Party) are both bowing down in homage, not to President Lincoln, but to the money his image appears on. The cartoon does not show government officials, but political parties. The cartoon does not say anything about Lincoln.