On who Ali G is
“The important thing about Ali G is that he's not black. And he is delusional, so he believes that he is a - you know, a black hip-hop artist from Staines, and you know, he believes that his neighborhood is a rough ghetto, when in fact it is this lovely, leafy middle-class suburb outside Windsor.”
Asked by Terry Gross to settle whether Ali G is a white or a Muslim hip-hop wannabe, he answered as himself. The interview was recorded in January 2007 while Borat was in theaters and rebroadcast on July 16, 2009, which is the transcript linked here. He added that whether Ali G is Arabic, Jewish or Greek does not matter: what matters is that he is deluded.
Source: An Interview With The Real Sacha Baron Cohen (Fresh Air, NPR) (npr.org). Wording checked against the source.
Character: Ali G