Earlier this month, the Supreme Court ruled in favor of a baker who didn’t want to make a cake for a gay wedding. Now, religious objection is in the news again, after 35-year-old Nicole Arteaga wrote a viral Facebook post about a Walgreens pharmacist denying her prescription for a drug used to end an unviable pregnancy.

Walgreens has apologized for how Arteaga’s case was handled, but it said that the employee had not violated company policy. There have long been rules in place that don’t require doctors to assist with medical abortion because of religious or moral obligations. This particular Walgreens is in Arizona, one of six states that lets pharmacies refuse to provide contraception as well, again on religious or moral grounds. Such behavior is protected by the so-called “conscience clause.” (In this particular case, the drug was not for emergency contraception. The baby had stopped developing and Arteaga had written that she would eventually have had a miscarriage.)

But how did the conscience clause develop, and how is it changing? The Verge spoke with Sonia Suter, a professor of law and bioethics at George Washington University, about the history and future of the conscience clause.

This interview has been lightly edited for clarity.

I know that Walgreens is allowed to deny service because of the so-called “conscience clause.” Can you give me some background on it?

The conscience clause came into existence after abortion was considered a constitutional right. Then, the Church Amendment passed with a strong vote in 1992, and it exempted private hospitals that receive funds from any requirements that they have to perform abortions. It was about religious objection and moral objection, and you have some variety of that at the state level, too.

Starting in the late ‘90s, when emergency contraception became widely available, you started seeing state laws dealing with this, too. Some people do view emergency contraception as a form of abortion, even though physicians would say it’s a form of birth control. Pharmacists started seeking the right to be able to not provide emergency contraception. Now, the real question is: how much are they allowed to decline? Can they just refuse? Do they have an obligation to refer? That’s where you see variations in state law.

In reality, what is the effect of a pharmacist declining to prescribe emergency contraception? How much effect does that have to access?

There are two issues. One is whether you’re allowing an individual pharmacist to refuse, and the other is whether pharmacies can just refuse to carry the medication. But, like all issues in reproductive care, it depends on where you live. We already have issues with access to abortion in rural areas. And especially if you have an entire pharmacy refusing to carry emergency contraception, you’re going to have real difficulty.

So it depends a great deal on location and your means, how easily you can travel, since timing with emergency contraception is really crucial. These restrictions on reproductive rights don’t affect women equally. Poor women and less well-educated women are affected by them much more. These restrictions are at best an annoyance, and at worst, they really limit access.

You mentioned that there’s a lot of debate over the details of how people can refuse to fill prescriptions. What exactly does that entail?

The Trump administration is really trying to expand the reach of conscience clause. It’s not just, “Can you refuse to provide abortion and medications to people?” It can possibly be interpreted as being so broad as to cover providing factual information. It could end up with a pharmacist saying, “I’m not going to give you any information on how you could get birth control,” though that would be fairly extreme.

It defines actors pretty broadly, so it’s not just employees, but anyone involved: volunteers, trainees, contractors, health care entities. And they’re also broadening it beyond religious objection to moral objection, and that has implications for other kinds of health care like vaccinations and gender reassignment surgery, too.

I don’t know how this will end up being implemented, but it is pretty Draconian. It really gets to the heart of these issues that keep popping up and going to SCOTUS about the tension between people’s right to equal protection and right to access medical procedures and, under the First Amendment, the freedom of expression and exercise of religion. How far can your First Amendment rights go?

A lot of people have been comparing this to the Masterpiece Cakeshop ruling about the baker who refused to make a cake for a gay wedding. On the face, they certainly look similar, but are they similar at the legal level?

Yes, though you’re talking about a conscience clause with respect to unions between people as opposed to a medical procedure. That said, the medical aspect adds another level. There’s really a public health interest in making sure people can get adequate health care. But I do think there are strong parallels to the Masterpiece Cakeshop case.

How has public opinion changed in regard to conscience clauses? Are they becoming more or less popular?

We’re a pretty polarized country, and it’s hard to say for sure. It depends on who you’re talking to. And there’s a growing movement to really protect the right to express your religious views and not have the government force the ACA or contraceptive mandate. Some of the religious right is growing, but you’re also seeing a growing opposition as well.

I think it’s one thing to allow people to not have to be forced to act against their conscience, but there has to be protections put in place so that other individuals aren’t denied access to things they are constitutionally entitled to and that they need for their health care. If we go too far in one direction, if we’re only protecting religious views, I think that’s a very scary place to be.

Correction 11:30 p.m. June 27, 2018: Nicole Arteaga was picking up a drug to end her failed pregnancy. An earlier version said that she had been picking up emergency contraception.