WASHINGTON – The Supreme Court’s 1973 decision in Roe v. Wade decision legalizing abortion in the United States may have created a decades-long debate, but on Wednesday the justices pondered a less prominent question—the legality of speaking about abortion near abortion clinics.

During oral arguments in McCullen v. Coakley, the justices considered the constitutionality of Massachusetts’ selective exclusion law, which creates a 35-foot buffer zone around reproductive health clinics that is off-limits to anyone not working for or seeking care at the clinic, or using the public sidewalk to pass by. Eleanor McCullen and others who said they simply wanted to counsel women seeking abortions on other options argued that the law is targeted at those speaking about abortion outside the clinics and, therefore, violates the First Amendment.

“The case the justices heard today represents a balancing act trying to ensure that those who object to abortion have a location where they can exercise their First Amendment rights of assembly and speech while at the same time providing a safe environment in which a legal business can operate,” said Ken Paulson, president of the First Amendment Center, in a telephone interview.

Buffer zones came to the Supreme Court’s attention in a 1994 case in which the court upheld Florida injunctions against protesters outside an abortion clinic. The topic was also brought before the court in 2000; the justices upheld a Colorado statute that imposed an eight-foot floating buffer zone around people entering and exiting a clinic within 100 feet of the clinic itself.

But while previous cases have discussed protests and assemblies, Mark Rienzi, McCullen’s attorney, argued that the Massachusetts law prohibits activists from even seeking to have quiet, non-disruptive conversations with clinic patients within the buffer zone.

The justices heavily questioned Massachusetts Assistant Attorney General Jennifer Miller about whether a less strict buffer is possible. Justice Anthony Kennedy raised concerns that the law implies no guarantee of free conversation for those walking near a clinic.

Vicki Saporta, president of the National Abortion Federation, which filed a brief supporting the Massachusetts law, said in an interview that the Massachusetts buffer zone is necessary to protect the safety of clinic patients and workers while still allowing anti-abortion activists a place to express their views.

“I certainly wouldn’t want to see an uptick in threats, obstruction and violence in Massachusetts or anywhere else where clinics have needed to obtain buffer zones to protect safe access,” she said.

She cited a history of violence around abortion clinics as reason to uphold the buffer zone law.

“What’s not clear is whether the Supreme Court will strike down a buffer zone, uphold a buffer zone or decide buffer zones have to be smaller,” Paulson said. “If the Supreme Court invalidates buffer zones, it depends on what grounds.”

Paulson said there is a “substantial chance” the high court will invalidate the Massachusetts buffer zone for being “too large a piece of public property to carve out and not allow free speech.”

If the court strikes down the law, other states may need to reassess their own buffer zone laws, he said.