A lot of what Obama has done, including the stem cell thing, is roll back Bush's executive orders with his own executive orders. Considering how well Bush was "loved", and how he crushed McCain, it's not exactly political suicide...
Hell, even Bush compromised on embryonic stem cells, by saying the ones in existence could still be researched. This was a boon for the University of Wisconsin, since we held many of those stem cell lines.
At any rate, the ban that Bush instated just seemed like a way to appease his Christian right base, and not something he really cared about...