Explain why you think Othello’s racial background does or doesn’t affect events in the play?

Othello's racial background affects events in the play in two ways: the way people think of Othello and the way that other people's reaction to Othello makes him think of himself.
Other characters in the play have reactions to Othello that range from exotic fascination to disgust. Iago hates him for reasons that are not entirely clear, but since he says "I hate the Moor," rather than "I hate Othello," race may likely be part of the reason for his hatred. Othello's race is certainly why Brabantio is unhappy that his daughter marries Othello; Othello is a reputed general in Venice, so his career or exterior social status is no reason to scorn him. Also, Brabantio is specifically unhappy that Desdemona would "fall in love what she feared to look on," that is, a black man. Brabantio's doubts about Othello make Othello judge himself as lacking later on, when he refers to his own "weak merits" to deserve Desdemona. In combination with Iago's possibly racially motivated hatred of him, Othello's doubt of himself leads to his believing that Desdemona must have cheated on him. So his own and other people's perceptions of Othello's race contribute to the play's tragic ending.