One of the top issues vocalized by Obama supporters during the election was the hope for "universal healthcare." It was a magic word, abused up and down by those with no understanding of the detriment such a system will reek on the American healthcare industry as a whole. Nevertheless, as Ezra Klein points out, "Universality means everyone has coverage, not just the ability to access it. And that requires a mechanism to ensure that they seek it."
As Philip Klein notes, this was one of the only big policy issues in which Obama and Hillary Clinton differed. If the mandates happen, he seriously mislead the American people in effort to obtain that middle ground he needed to push forward.