god is not racist the authors were. if you write that your people are gods chosen and are responsible for spreading 'his' word (their own variant) then it strokes the populaces egos and makes them feels superior. think about ancient greeks, anyone not greek was a 'barbarian' and not as sophisticated as the greeks, giving the greeks a superiority complex.
It may stroke the ego, but on the other hand, look what else these "racists" said about themselves (putting these words in the mouth of God no less). Note that in the day, the size of the nation's population was taken to be a sign of divine blessing and/or approval:
It was not because you were more numerous than any other people that YHWH set his heart on you and chose youfor you were the fewest of all peoples. It was because YHWH loved you and kept the oath that he swore to your ancestors, that YHWH has brought you out with a mighty hand, and redeemed you from the house of slavery, from the hand of Pharaoh king of Egypt.
Deuteronomy 7:7-8
In other words, there was nothing so very great about them that caused God to honour them or choose them. No ego-stroking there.
Besides, if a sense of racial superiority was what motivated the conquest of Canaan and the destruction of its inhabitants, why wasn't the task carried through? And why was this logic not carried through to become a central part of the Israelite ethic (for example, as we saw in the US where racism became a central part of the nation's ethic with Jim Crowe laws)? Indeed, it seems the opposite is true:
there shall be one law for the native and for the alien who resides among you.
Exodus 12:49 (contrast this with the Jim Crowe laws)
You shall not oppress a resident alien; you know the heart of an alien, for you were aliens in the land of Egypt.
Exodus 23:9
The racist interpretation, whether applied to God or the authors of the bible simply makes no sense.
Now of course, we might argue that at times, Israel did not conduct herself according to her best lights. Fair enough. But we are here asking whether racism formed the basis of Israel's ethic. Clearly it didn't.