Why will we keep hearing about embryonic stem cell research?

Here's a good article by Yuval Levin on stem cell research focusing on how embryonic stem cell research hasn't become the wedge issue many Democrats hoped it would and why some Democrats will continue to use this issue.

But if most voters seem relatively indifferent to the issue, why have stem cells taken such a prominent place in the liberal political imagination? Some on the Left have surely bought the hype and think the future of medicine is on the line — and that, as Democratic Rep. Diana DeGette of Colorado preposterously claims at every opportunity, embryonic stem cells will "cure diseases that affect 110 million Americans and their families." But for many on the Left who realize that not every third American is dying of a degenerative illness and that the therapeutic potential of embryonic stem cells remains for now thoroughly speculative, the issue nonetheless resonates, and for reasons that run deep.

The issue offers, for one thing, a foil for the abortion debate. On abortion, the Left finds itself defending an increasingly abstract notion of freedom against (thanks to improving imaging technology) an increasingly concrete case that a human life is at stake. When it comes to stem-cell research, it is pro-lifers who find themselves making an abstract case for the humanity of a ball of cells, while their opponents can point to very concrete sick children and adults whom they claim could be helped by the destruction of embryos. It offers the Left a compassionate "health care" dimension to the case against the humanity of the unborn.

What is more, it allows the Left to claim the authority of science in its fight against conservatives. By depicting opposition to the destruction of nascent life for the sake of medical research as opposition to the progress of science, liberal embryonic-stem-cell advocates can position themselves where they most like to imagine themselves: as partisans of progress, struggling against reactionary and religious zealots who champion only ignorance and pain. Never mind that pro-lifers are defending the liberal ideal of equality by making a case grounded thoroughly in embryology, and never mind that the supposedly scientific case to the contrary amounts to "embryos are awfully small and don't look like anyone I know." For many on the Left, this is a fight between science and religion, and therefore the epitome of a progressive struggle.