Sanders' campaign policy director, Warren Gunnels, said in a statement Saturday that Sanders "strongly supports stem cell research, including research on embryonic stem cells. He understands that stem cell research holds the possibility of remarkable discoveries, even cures, for many illnesses — from Parkinson's and diabetes to Alzheimer's and arthritis." He noted that Sanders supported 2006 legislation to lift funding restrictions on embryonic stem cell research.
While serving in the House, Sanders voted to ban therapeutic cloning in 2001, 2003 and 2005 as Congress grappled with the ethics of biotechnology and scientific advances. Patient advocacy groups note that Sanders co-sponsored bans in 2003 and 2005 that included criminal penalties for conducting the research and opposed alternatives that would have allowed the cloning of embryos solely for medical research.
Clinton, meanwhile, co-sponsored legislation in 2001 and 2002 in the Senate that would have expanded stem cell research and co-sponsored a bill in 2005 that would have banned human cloning while protecting the right of scientists to conduct stem cell research.
Sanders said following a vote in 2001 that he had "very serious concerns about the long-term goals of an increasingly powerful and profit-motivated biotechnology industry." In a later vote, he warned of the dangers of "owners of technology" who are "primarily interested in how much money they can make rather than the betterment of society."
Gunnels said that "therapeutic cloning is a good thing, but only with proper oversight and regulations. The reality is that the corporate biotechnology industry is motivated almost exclusively by their quest for short-term profits and higher stock prices. There must be proper oversight over this industry."
Some advocates for stem cell research said that overlooked the potential benefits of finding possible cures to Alzheimer's, Lou Gehrig's and other fatal or disabling diseases.
"Sanders and (then Republican House Majority Leader Tom) DeLay — some unlikely group — were just unyielding and they were part of the religious right's attempt to shut down this whole critical new frontier of therapy for chronic disease," said Robert Klein, chairman of the California Institute for Regenerative Medicine.
"It's fine to say you're for stem cell research but you vote against it and you vote against all therapeutic application, it doesn't mean anything to say you're for it," Klein said. "Fine, he votes for it years later when it's more popular and the pressure is off. We needed leadership then."
Embryonic stem cells are master cells that can turn into any tissue of the body and researchers hope one day to harness that power for what's today typically called "regenerative medicine." Initially, they were derived by using leftover embryos from in vitro fertilization clinics.
Therapeutic cloning is another method of deriving those cells.
Exactly what types of stem cell research to allow, and how to fund it, have been debated not only on the national level but in a number of states including Wisconsin, where researchers played key roles in some early discoveries. Wisconsin holds its presidential primary on Tuesday.
Federal law prohibits taxpayer funding of research that harms embryos so that early work was done with private money. But those types of cells can reproduce indefinitely in lab dishes, "lines" used for a variety of research projects.
After much controversy, the Bush administration declared that taxpayer money could be used for research using certain already-created embryonic stem cell lines and President Barack Obama expanded the number that qualify, a move that survived court challenges.