It has nothing to do with race. I'm not going to play this game with you MM, because the things you seem to think are "facts" are usually not facts at all, just information from some publication you think has merit over another.
Carson has written a book that contains some untruths. He has said he did not endorse or have a relationship with a company for some kind of supplements that he clearly did endorse. He's not the President and we're not talking about interpretations of national events; he's talking about the facts of his life. If you lie about your life, what else will you lie about? He's hardly the first or the last person running for office that is capable of double-speak; but I won't vote for him because I don't think he is up to the job.
As far as Obama, I don't think he has lied about his life. He, like so many other politicians, has not always been truthful about events. I seem to recall that we never did find out the real story about what happened during Katrina that left so many U.S. citiziens in a mess while GWB was patting "Brownie" on the back. You don't like Obama, I don't like Carson, you liked GWB and I did not. So why don't we just leave it there?