Some will argue that swearing on the Bible ensures the president adheres to his oath.

CNN: Presidents should not swear in on a Bible

Barack Obama has made a concerted attempt to present himself as a latter-day Lincoln, keeping a portrait of the martyred president on his desk and taking his oath of office on Lincoln's Bible.

ECONOMIST: Lexington

Barack Obama took the oath of office on the same King James Bible that had been used by Abraham Lincoln in 1861.

ECONOMIST: Prepare for a celebration of biblical proportions