Anti-choice conservatives want the public to believe that abortion and birth control are the same thing so that it becomes impossible to access both. But because openly going after birth control has shown itself to be a form of political death, politicians and anti-choice advocacy groups have been working to conflate contraception and abortion when it’s politically convenient. The lie is by design, and it’s working.

It’s no accident that Hobby Lobby contested the birth control requirement of the Affordable Care Act on the grounds that it believed, despite overwhelming medical evidence, that some of the contraceptives covered were abortion-inducing drugs. And that this line — that emergency contraception and IUDs end rather than prevent pregnancy — has found an audience with Supreme Court justices, politicians, media pundits and regular people.

This has felt like something of an open secret for the last few years, as the parallel assaults on birth control and abortion have only accelerated, but a new report from the Guttmacher Institute has made the right’s anti-contraception, anti-abortion dual strategy clear. It’s a selective campaign of misinformation and phony science driving both efforts, but deployed selectively in an attempt to conceal a profoundly radical agenda.

“Rather than applying the claim that some contraceptive methods in effect cause abortion consistently to all aspects of their advocacy, antiabortion groups ignore and often contradict their positions when it might hurt them politically,” according to Joerg Dreweke, author of “Contraception Is Not Abortion: The Strategic Campaign of Antiabortion Groups to Persuade the Public Otherwise.”

Guttmacher examined the strategies of antiabortion groups like Americans United for Life, the Heritage Foundation and the Susan B. Anthony List and found that each referred to the contraceptive requirement of the new healthcare law a form of abortion coverage. The AUL called it a “back door abortion mandate” to cover “life-ending drugs that have been deceptively labeled as contraception.” The SBA List list has called it, simply, an “Abortion Drug Mandate.”

This is the same bogus science that was used to defend Hobby Lobby in its challenge to the healthcare law. Conservative justices eagerly parroted it back. During oral arguments in the case, Justice Antonin Scalia said, “You’re talking about, what, three or four birth controls, not all of them, just those that are abortifacient.”

Contrary to arguments made in the Hobby Lobby case and repeated elsewhere, there is no credible medical evidence to support the claim that emergency contraception like Plan B and ella prevent fertilized eggs from implanting in the womb. Those medications work by delaying ovulation. Hormonal IUDs thicken cervical mucus to prevent sperm from reaching the egg. When used as a form of emergency contraception, the copper IUD can interrupt implantation, but this still does not mean a pregnancy has occurred.