The recent controversy about Planned Parenthood and fetal tissue donation suggests that highly publicized bioethical issues generally benefit conservatives. In fact, quite the opposite is the case. Since 2000, when bioethics issues (apart from abortion) have come on on the radar, they have aided the country’s leftward move on social values.

This trend has unfolded in spite of a determined effort by conservative policy intellectuals to use bioethics as the tip of their spear. In 2003 the conservative policy intellectual Yuval Levin urged like-minded readers of The New Atlantis to take note of “a key conservative priority,” the study of bioethics. To conservatives, Levin said, a focus on bioethics was natural. “Some American conservatives have long shared the concerns that animate bioethics,” Levin wrote. “The pro-life movement has always worried deeply about the treatment of the unborn by scientists and doctors, and many conservatives have through the years been interested in various issues surrounding medical ethics, illicit drug-use, assisted suicide, and other social and cultural matters that have much to do with modern science. But,” he concluded, “it was not until fairly recently that bioethics emerged as a general and prominent category of concern for the American right.” The trajectory of Levin’s work in the early 2000s reflected bioethics commitments, including staff positions on President George W. Bush’s bioethics council and the White House Domestic Policy Council, and several articles and books. Bioethics was, Levin argued, “a key priority of the American right.”

If bioethics was indeed a “key priority” of the American right ten years ago, that priority has virtually disappeared. Since the end of the Bush Administration, Levin’s career has reflected conservative thinkers’ turn away from social issues, including bioethics. Now the editor of National Affairs, Levin has been identified in this journal as one of the “reformicons,” a small group of reform conservatives who have little to say about cultural matters, concentrating instead on the future of the American economy and American jobs.

It’s hard to find a conservative intellectual who emphasizes bioethics anymore, a sea change from the era of Bush 43, who devoted a chapter of his memoir, Decision Points, to the debate about human embryonic stem cells. One explanation for this change is that the country has simply moved on to more pressing issues after the Great Recession, and the reform conservatives have moved apace. Another (and a false one) is that many of these formerly contentious questions have been settled. But there is, I think, a more accurate and complete explanation.

Far more than most liberals, Levin and other social conservatives appreciated the importance of bioethical issues in the new century. They understood that these problems have a peculiar symbolic force. Therefore it was critical to frame the bioethics debate. But, from their point of view, there have been repeated disappointments, even during the Bush years when the bully pulpit should have been theirs. More recent events have only confirmed their strategic decision to leave the field, however reluctantly. Simply put, for all its passion and focus, the conservative bioethics project failed. But why did it fail, and how?

Consider just two of the specific items on Levin’s 2003 list: illicit drug use and assisted suicide. Laws recognizing the medical uses of marijuana are now on the books in 23 states and the District of Columbia. Perhaps these statutes are a stalking horse for illicit recreational use—which is already allowed by some states—but they are firmly in place with more to come. Similarly, medically assisted death statutes are on the books in several states and are being debated in several more. Seeing the suffering of their elderly parents, aging Baby Boomers seem unimpressed by worries that such arrangements represent a “culture of death” rather than self-determination.

Then there is the matter that most animated those who professed conservative bioethics: stem cells. When President Bush announced his policy in August 2001, advocates on both sides noted somewhat uneasily that he had, in effect, split the difference. Opponents of using cells cultured from embryos in the laboratory were pleased that he called a halt to federal funding for creating new cell lines, while the scientific community was relieved that funding of research on existing lines would continue. As the years unfolded, however, the limits on stem cell culturing came to signify an “anti-science” attitude in the White House, intensifying conservative hopes that an acceptable alternative to embryonic cells could be found. When a Japanese team announced in 2007 that they had turned adult cells into cells that closely resembled embryonic stem cells, conservative commentator Charles Krauthammer (trained in psychiatry but not molecular biology) claimed a “stem cell vindication.” But it turned out that the new, induced pluripotent stem cells weren’t as useful in the laboratory as the ones cultured from embryos. By the time the 2008 Republican presidential candidate John McCain refused to commit to halting embryonic stem cell research, the air had gone out of what was always an arcane issue.

Recently a Wall Street Journal/NBC News poll found that, since 2010, the percentage of self-identified liberals had increased from 23 percent to 27 percent, while self-identified conservatives dropped from 37 percent to 33 percent. Noting those results, as well as similar data from Gallup polling, The Washington Post’s Dana Milbank suggested that the word liberal is no longer tainted, citing a list of issues that have worked against social conservatives, including stem cell research. The seismic shift in attitudes toward gay marriage has also changed the way many Americans think about what it means to be liberal, Milbank argues. And though gay marriage is not on its face a bioethics issue, it has a way of carrying other non-traditional family-making arrangements along with it, like in vitro fertilization and surrogate motherhood.

Obamacare, perhaps the most important domestic legislative event since the Great Society, may also spur a second look at “liberalism” and a resistance to conservative policy solutions. Although the moral argument for health care reform had barely any salience in the political debate, now that the Affordable Care Act has passed two major legal challenges the notion that all Americans deserve decent health insurance will help enshrine an expanded government role in providing for the common good—an outcome that bioethics conservatives hoped to avoid by aligning themselves with a voucher-based system.

It is far too soon to know how the current controversy about fetal tissue research will play out. Remarkably, during all the years of debate about embryonic stem cells, pro-life groups said next to nothing about fetal tissue donation. The issue was first debated in the 1970s but has been dormant since 1988, when a Reagan-appointed panel found medical research involving legally aborted fetuses acceptable. The Clinton, Bush, and Obama administrations have all funded this work. Once the dust settles, it is likely that the reasons for continuing to use fetal tissue will become clear. For example, the bipartisan Brain Initiative has targeted understanding dementia and traumatic brain injury. Understanding how neural tissue develops in the fetal brain could be a key to new therapies.

Social liberalism doesn’t translate into economic liberalism, as the Trans-Pacific Partnership Agreement suggests. And there’s a strong dose of libertarian as well as liberal appeal in many bioethics issues, particularly the Terri Schiavo case. With two major candidates from Florida, that catastrophic political intervention into what should have remained a family tragedy will once again underline the way that bioethics issues have inured to the benefit of the American left.