“This case involves express discrimination based on religious identity with respect to playground resurfacing,” Chief Justice Roberts wrote. “We do not address religious uses of funding or other forms of discrimination.”

The Trinity Lutheran decision, however, noted that a church could not be barred from participating in a grant program “simply because of what it is — a church.” In New Jersey, the historic preservation program involves grants, leading some legal experts to say that could provide the basis of a challenge to the Supreme Court.

“The historic preservation value is sometimes understood like what the church looks like when you walk by, versus what it looks like or operates inside,” said Ira C. Lupu, a law professor at George Washington University who closely followed the Trinity Lutheran case. Essentially, repairing a facade or a roof does not directly affect how a congregation worships or practices. But he also noted that some of the grant money in the New Jersey case was used for stained glass windows, and that those amenities could be interpreted as directly affecting a religious service or practice.

“The county has a secular purpose in the historically accurate appearance of the roof and facade, but the county’s purposes seem far more religious if it is renovating stained glass windows, which affect the experience of the service,” Mr. Lupu said.

The case in New Jersey dates to 2012, when David Steketee, a resident of Madison, was walking in nearby Morristown and noticed a sign outside the Church of the Redeemer near the town’s historic green.

“They had a large placard out front thanking whatever historic preservation trust fund for money that was donated to it,” said Mr. Steketee, 41, who works in information technology but has an “armchair scholar” interest in the Constitution. “I thought it was interesting that the tax dollars would go toward preservation and restoration of a church.”

After communicating with national groups to amplify his complaint, Mr. Steketee found an ally in the Freedom From Religion Foundation, a group, based in Madison, Wis., that regularly fights for the separation of church and state. (The music the group plays for callers put on hold is a homespun jingle: “I’ve heard about your hero Joshua, but his accomplishments are not so great. Because there’s none like Thomas Jefferson, and the wall between church and state.”)