The stem cell research ban was technically on embryonic stem cell research only (and from what I remember lines that already existed were 'exempt'), but that does not change the fact that researchers using any stemcells at all found their chances of getting funding drastically reduced.

There are afaik three sources of stem cells, adult ones, embryonic ones and stem cells taken from umbilical cord tissue.

The ban itself stemmed from a very bad mixing up of religion and politics.

As I understand it, embryonic stem cells (the ones that were banned) are acquired by basically destroying a human embryo. I don't think it is "very bad mixing up of religion and politics" to ban destroying what can be considered a life. You might disagree whether the life is worth saving, but the embryo is undeniably living. You might disagree as to whether a human embryo is human enough that killing it constitutes killing a person. But if one's religious ethics are that killing an embryo == killing a person, I think it is reasonable politics to ban embryonic stem cells.

EDIT: clarity

As I understand it those embryos were going to be destroyed anyway. The difference being that now they might be used to further research. It's not like the embryos were created to be destroyed for research, they're a by-product of fertility enhancing procedures.

In the interest of empathizing with the other side, here's what this sounds like if you're pro-life: "As I understand it, there were Africans who were going to die in Africa anyhow. The difference being that now we might get some use out of them. Its not like we went to Africa for the slaves, they're just a by-product of the resource exploitation."

That's one of the most warped analogies that I've ever seen.