That's a question we all need to seriously ask ourselves. For we all will have to give an account for the deeds done while we professed being a Christian. I will leave the judging up to GOD. He will have the last and final say anyway.

If Obama was a Christian, he wouldn't do any of the Racist things he's done. IMHO, if he had sat down and asked for guidance from God/or the Lord Jesus Christ, for some of the things he's done we wouldn't be at a cross road of Leadership or Racism as we are now. There is definitely NO Leadership and Racism is worse since he has taken office. No, I don't believe he is a Christian.
Anyone can go into a church, but if you let the teachings go in one ear and out the other, it doesn't make you a Christian.

Racists and bigots are Christians in their own mind. All one has to do is study history. Whether one believes someone else is a Christian or not, what we think is folly to God.

James 2:10 For whoever keeps the whole law and yet stumbles at just one point is guilty of breaking all of it. Now, that is very fitting I might add.

1 John 1:8 If we say that we have no sin, we deceive ourselves, and the truth is not in us.

1 John 2:4 He that said, I know him, and keeps not his commandments, is a liar, …

This sums it up.

Proverbs 6:16, 17 and 19 – There are six things that the LORD hates, seven that are an abomination to Him: haughty eyes, a lying tongue…a false witness who breathes out lies. Yep, that describes and sums it up.

So you are saying James 2:10 For whoever keeps the whole law and yet stumbles at just one point is guilty of breaking all of it.

So if you believe that demons are a myth (as stated by you) when Jesus and his disciples say that they are real, then James 2:10 applies to you.