SAN FRANCISCO (CN) — A federal judge Thursday played devil’s advocate in the four-year battle between Berkeley and the U.S. Postal Service’s proposed sale of a historic Post Office building, telling them to get ready for a trial in which he wants to see “witnesses up here being hammered and beat up, and blood on the floor.”

U.S. District Judge William Alsup, however, offered few solid clues on whether he would dismiss the government’s lawsuit, as Berkeley wants. He spent a fair amount of time at the hearing discussing hypothetical scenarios of a trial, indicating that he may deny Berkeley’s motion to dismiss.

“If the case goes forward, I want you to be thinking about trial, cross-examinations; I don’t want you thinking ‘summary judgment,'” Alsup said. “I want witnesses up here being hammered and beat up, and blood on the floor.”

The Postal Service sued Berkeley in July, claiming the city interfered with its mandate under the Postal Reorganization Act to sell the 102-year-old building, by passing a zoning ordinance restricting the building to civic and nonprofit uses.

In its motion in opposition, the Postal Service says the ordinance scared away buyers, who will not pay a suitable price for a building with restrictions on its commercial use. It claims the city’s restrictive rezoning violated the Constitution’s Supremacy Clause and improperly preempts federal law.

With fewer customers and shrinking revenue, the Postal Service announced plans in 2011 to close as many as 3,700 branches nationwide.

As part of its cost-cutting, the Postal Service said it would sell its main post office building at 2000 Alston Way in Berkeley, as it needs only 4,000 square feet of the 57,000-square-foot building.

Seeking dismissal Thursday, Berkeley City Attorney Zach Cowan told Alsup the zoning ordinance does not affect the Postal Service.

In its motion to dismiss, Berkeley said the ordinance affects the Postal Service only indirectly, imposing a financial burden on it by regulating potential buyers, but that that neither preempts nor violates the Constitution.

“The federal government’s powers and activities are unaffected,” Cowan told Alsup. “The consequences of those activities may be changed, but we change the consequences of the public’s activities all the time. That’s the nature of zoning.”

Only nine downtown buildings were rezoned, most of them owned by the city, according to Department of Justice attorney Julia Berman. In its opposition to dismissal, the Postal Service said that the rezoned area is so irregularly shaped it smacks of gerrymandering.

“The effect on the ground of this ordinance fell solely on the Postal Service,” Berman said. “The zoning ordinance now makes it highly unlikely a sale will ever occur.”

Alsup, noting that the Postal Service’s case relies on its argument that it won’t be able to find a buyer, said it would need to present proof of that at trial.

He pointed out, however, that the Postal Service doesn’t have a real estate broker who could testify at trial that he or she failed to sell the property despite multiple attempts.

“That would tee it up nicely for you, but now you want me do it on a hypothetical basis,” Alsup told Berman. “There goes your best witness.”

Alsup also said he wants the Berkeley City Council deposed, noting that “no one is going to buy this building unless they can use it for commercial purposes.”

The Postal Service says the City Council discussed the zoning ordinance as a tool for blocking the sale of the building, and Mayor Tom Bates even told a newspaper that “this is a good way to do it.”

Alsup closed Thursday’s hearing on a nostalgic note, saying that Post Office buildings symbolized the “heart” of bustling downtown districts throughout the nation for people such as him, who grew up in the 1940s through the 1960s.

“It’s an important part of America,” he said.

Trial has been set for Dec. 4, 2017.