Last month, Governor Baker indicated that he was not interested in establishing a passport in Massachusetts that would allow vaccinated residents to access certain venue services or events in other states like New York. Northeastern University law professor and GBH News legal analyst Daniel Medwed joined GBH’s Morning Edition today to talk about the legality of vaccine passports. This interview has been edited for clarity and length.

Joe Mathieu: We always start big picture. Let's do that today. The phrase “vaccine passport” is kind of an umbrella term that applies to any number of requirements. And people must show proof of vaccination against COVID to access services. But to get on a plane or to travel out of the state, in many cases, they're not being used yet. But this could be something that is our reality. What are the legal arguments for and against?

Daniel Medwed: You're exactly right — vaccine passports are different from vaccine mandates, which really aren't on the table right now. They're often talked about as digital health passes, where you would show proof of vaccination on your mobile device to gain entrance to a range of venues and services, as you point out — to let you go to the gym or to go back to the workplace for in-person activities.

The main arguments in favor of these vaccine passports are first, that it's just a natural outgrowth of the state's authority to regulate during public health crises. It's just an extension of the mask mandates or the travel quarantines or any number of COVID restrictions. A second argument is that private businesses have a profound interest in the health and safety of patrons and employees and that they deserve to have some discretion, a little bit of difference in how they structure their activities to protect their own.

The main argument against it, of course, revolves around individual liberty, the idea that citizens shouldn't face pressure to divulge what is arguably private health care information, whether they've been vaccinated, let alone pressure to maybe make a health care decision that runs counter to their values and desires.

Mathieu: We're talking about a government passport here, right? As opposed to something that a private company might decide to do on its own.

Medwed: I think that's right. It could be sort of a fusion. So, for instance, what's happened in New York is that New York state is working to set up these voluntary passports, but there's a buy in or opt in from private businesses like Madison Square Garden.

Mathieu: So that said, Daniel, what are the arguments against these passports? Do they have legal merit?

Medwed: Like so many things, Joe, the devil's really in the details. On the one hand, restrictions like this — there's a long standing tradition of it. Most of us, or many of us, are familiar with how you have to show proof of vaccination to get your kid enrolled in many schools or to get a bed at a college dormitory. Also, businesses, of course, have a number of restrictions as a prerequisite to gaining entrance. You have to wear shoes to go to a restaurant. You have to show proof of age to get a beer, things like that. So I think that these passports would probably pass legal scrutiny so long as they don't interfere directly with constitutionally protected interests. [As in,] you don't have to show vaccine passports to vote or to participate in a public demonstration or to go to religious services.

WATCH: Daniel Medwed on the legality of vaccine passports

Mathieu: Got it. The federal government, I'm assuming, could impose a form of vaccine passport, some requirement on the national level, but that would be very controversial.

Medwed: I think you're right. I doubt that's going to happen, not only because of the political ramifications. Getting that through Congress would be a nightmare, but also because Congress would have to set up appropriate jurisdiction for it. They'd have to show how these measures are designed to prevent the interstate transmission of COVID. And there are many on-the-ground situations where that might be difficult to show.

Mathieu: I want to ask you about the state level here, preventing a business from requiring a vaccination before accessing a ballpark or a concert or something. How does that run on the legal standpoint?

Medwed: That is a hot button issue, Joe, in places like Florida and Texas, where the governors have issued executive orders saying businesses may not require vaccine passports. Governor DeSantis in Florida is in a real pickle — he's fighting with the cruise industry and the CDC and the CDC is basically saying you have to have a 98 percent vaccination rate to send your ships out into ports of call across the world. And DeSantis is saying: No, if you want to base your cruise ships in Florida, you can't have that requirement. It'll be interesting to see how that one plays out.