Google auto complete is based off Google searches. When you type something in it starts looking at a massive database of all searches by that word, as you add words it auto completes by adding in words that come up as a majority of other searches. Thus the results when you put in Obama is a ... Try it with George Bush and you'll get similar results.

"Guard well the words you use, for they can be the keys to your freedom or the manacles of your slavery." - me