Barack Hussein Obama is a Muslim. He has a Muslim name. He has a Muslim father. He was raised in a Muslim country. He speaks lovingly of the Muslim 'call to prayer'. He attended a church headed by an "ex"-Muslim, who sounded more like a current Muslim than a Christian. He supports Muslim countries, alienates non-Muslim countries. He dropped a line about his 'Muslim' faith.
There is very little evidence, if any, that he is anything but a Muslim.