Iago's hatred for othello increases throughout the play. Explain why he is consumed by racism, paying particular attention to his hatred for "The Moor" and his interracial marriage to Desdemona.
I love Shakespeare, and it has been awhile since I read Othello, but I pulled it out happily when I saw your post. :) I will do my best to answer your question, and I will also give you several websites that can help you understand this theme better. It can be difficult to interpret Shakespeare and to comb through for examples if you're not used to it. Hopefully this will help.
There are a couple of different interpretations about why Iago hates Othello and basically destroys his whole life. Critics disagree about whether the rascism is the main motivator for Iago, and they point to Iago's given reason for hating Othello. It is probably too simplistic for such a complex character as Iago, but it is the only one directly stated in the play. According to Iago, he hates Othello because he passed him over for a promotion. Othello ...
An analysis of Iago's hatred of Othello, due to rascism