If Obama wins does that mean he is appointed by God to be President? I would say, Yes.
I don't believe there is any power that God hasn't appointed, even evil leaders.
What does the Bible say of such things?
For there is no authority except from God, and the authorities that exist are appointed by God. Romans 13:1
A good example of God appointing an evil leader is found in King Nebuchadnezzar. In Jeremiah we find God saying that He was summoning the Kingdom of the North (Babylon) to slay the children of Israel.
Daniel says this to arrogant King Nebuchadnezzar, "They shall drive you from men, your dwelling shall be with the beasts of the field, and they shall make you eat grass like oxen. They shall wet you with the dew of heaven, and seven times shall pass over you, till you know that the Most High rules in the kingdom of men, and gives it to whomever He chooses. Daniel 4
And after seven years we find God giving King Nebuchadnezzar the Kingdom back.
What does God say of evil Pharoah?
For the Scripture says to the Pharaoh, “For this very purpose I have raised you up, that I may show My power in you, and that My name may be declared in all the earth.” Romans 9
Notice it was God who raised him up.
We also find in Israel that the people wanted a King, which was not what God wanted, but because of the hardness of their heart He appointed King Saul, who ended up evil. Then He appointed David.
Christians can be certain if Obama is elected God appointed him, but still we should always oppose anything he does or approves that is immoral or unethical, and even God Himself will judge concerning such things.