Here is some ammunition for "birthers". Here is a video from 2007 where Michelle Obama refers to her husband as a "Kenyan".
At about two minutes into the video, she says, "What it reminded me of was our trip to Africa, two years ago, and the level of excitement that we felt in that country – the hope that people saw just in the sheer presence of somebody like Barack Obama – a Kenyan, a black man, a man of great statesmanship who they believe could change the fate of the world."
http://www.wnd.com/index.php?fa=PAGE.view&pageId=150505