Although the play may not seem to be about politics, its presentation of Othello as black and older than Desdemona clearly raises crucial issues of race, age and culture. In the 20th century the play proved a significant symbol in the struggle for black emancipation. A long running American production in 1943 included the first ever kiss on stage between a black man and a white woman. All later productions in America commented with varying directness on the Civil Rights movement for equality between races.
Similarly, in South Africa, a famous production at the Market Theatre, Johannesburg became a potent focus for the anti-apartheid campaign. Iago was portrayed as an intolerant Afrikaaner and Othello was played by a township black. Today fierce debate rages as to whether only a black man should play Othello. A 1999 production in Washington found a solution by casting a white actor as Othello and having every other character played by black actors.
(source: p. 51, Shakespearean and Jacobean Tragedy by Rex Gibson, 2000)
Take the time to look at how Othello has been cast over time here.