How can Cruz get away with such blatant nonsense when it comes to the lessons that science and medicine have to teach about embryos and fetuses? It is partly because the medical and bioscience communities long ago abandoned any serious effort to shape the debate over abortion. Many, I suspect, don’t want to alienate the main source of their financial support—Congress and state legislators. They have decided to stay out of the whole divisive issue leaving pro-life politicians like Cruz to make claims that are just as much junk science as climate denial, creation ‘science’ and efforts to link autism to vaccines.

A good number of scientists and doctors hide behind the claim that science cannot tell us anything of relevance to abortion. This attempt to evade any relevance to the battle over abortion started with a U.S. National Academy of Sciences statement in 1981 that the existence of human life at conception is a question to which science can provide no answer. Since that time, most life scientists and physicians have remained more or less mum on the issue of abortion. Their reticence permits Cruz to invoke biological science and medicine in ways not supported by either.

While it is absolutely true that the law or theology have the power to stipulate when both human life and legal personhood begin, it is also true that science and medicine have in their possession facts that bear on the answers to those questions. Oddly, that is something that Ted Cruz seems willing to acknowledge even if many scientist don’t. The unwillingness of scientists and doctors to counter misstatements like Cruz’s only lets them flourish.

So what about fetal pain? Cruz and proponents of fetal pain laws requiring fetal anesthesia as part of any abortion at 20 weeks of the sort just enacted in Utah insist that science and medicine hold that fetuses at 20 weeks feel pain. Cruz is even hinting that embryos do, which is absolute nonsense. However, so is the claim about 20-week old fetuses. No studies demonstrate any such capacity.

In 2010, Britain’s Royal College of Obstetricians and Gynaecologists reviewed the available evidence and concluded that the “fetus cannot feel pain before 24 weeks because the connections in the fetal brain are not fully formed.” Further, they said, the fetus, “while in the chemical environment of the womb, is in a state of induced sleep and is unconscious.” The main American article on the subject published in 2005 in The Journal of the American Medical Association reviewing over 2,000 articles on the ability of the fetus to feel pain came to the same conclusion. The fetal brain at 20 weeks is not wired sufficiently to feel pain.

Legislators who despise abortion may not care. They want to pass laws prohibiting abortion at 20 weeks or earlier. But those who do, like Ted Cruz, should not get a pass on citing false medical or scientific in support of their moral point of view. As the Utah law shows bad science makes for bad public policy.