In a 2001 Illinois Senate floor speech about that bill, [Obama] argued that to call a baby who survived an abortion a "person" would give it equal protection rights under the 14th Amendment and would give credibility to the argument that the same child inside its mother's womb was also a "person" and thus could not be aborted.

When the Illinois Senate bill was amended to make it identical to a federal law that included language to protect Roe v. Wade--and that the U.S. Senate voted unanimously to pass--Obama still opposed the bill, voting it down in the Illinois Senate committee he chaired.
http://www.crosswalk.com/news/religiontoday/11569732/

During a debate against Keyes in March 2004, Obama rationalized: "Now, the bill that was put forward was essentially a way of getting around Roe vs. Wade, which is why 21 other senators, Democrat and Republican, why the Illinois Medical Society objected to the bill. At the federal level, there was a similar bill that passed because it had an amendment saying this does not encroach on Roe vs. Wade. I would have voted for that bill."
http://www.wnd.com/news/article.asp?ARTICLE_ID=53617

On the topic of abortion, Obama said his support for keeping it legal does not trespass on his Christian faith.

"I think that the bottom line is that in the end, I think women, in consultation with their pastors, and their doctors, and their family, are in a better position to make these decisions than some bureaucrat in Washington. That's my view," Obama said about abortion. "Again, I respect people who may disagree, but I certainly don't think it makes me less Christian. Okay."
http://www.crosswalk.com/news/religiontoday/11569732/

An Obama spokesman told the Chicago Tribune in August 2004 that Obama voted against Born Alive because it included provisions that "would have taken away from doctors their professional judgment when a fetus is viable."

Obama told the Chicago Sun-Times in October 2004 he opposed BAIPA because "physicians are already required to use life-saving measures when fetuses are born alive during abortions."