My daughter was listening to the area's main Christian radio station, and heard a clip of a certain presidential candidate voicing his stand on civil unions and such.  It took less than a minute for me to find online at least one news article with voice clip of Senator Obama explaining himself. 

"If people find that controversial then I would just refer them to the Sermon on the Mount, which I think is, in my mind, for my faith, more central than an obscure passage in Romans."

I don't think chapter 1 of Romans is exactly "obscure".  The article does not indicate in what way the Sermon on the Mount justifies supporting civil unions.  Maybe Obama should go back and check out Genesis, as well, where we find the creation of man and woman:

So God created man in His own image; in the image of God He created him; male and female He created them. (Genesis 1:27)

That's another "obscure passage", right?  And a man leaving his mother and being joined to his wife?  Genesis 2:24, Matthew 19:5, Mark 10:7, and Ephesians 5:31. 

You can find the specific article that I found here, voice clip included as a link within the article.

For someone portraying himself as a "devout Christian", he may need to do a little homework.  In this Christianity Today interview, he was asked if he was a "born again" Christian.  He avoided using that terminology.  He never stated that he was born again.  There's a difference between "devout" and "born again".   He doesn't talk about a saving knowledge of and relationship with Jesus Christ.  I'm convinced he has a relationship with a particular church, but not convinced that he is connected in a personal relationship with the King of Kings and Lord of Lords.  Not that my opinion matters.