The battle over how to handle Pennsylvania’s congressional maps has even political families divided.

Former governor Dick Thornburgh has filed a brief to the United States Supreme Court arguing a new congressional map drawn by the state Supreme Court should be invalidated.

But the governor’s son, David, has called that map an “improvement” on the old one.

The elder Thornburgh’s gripe over the court-drawn map is the same as other GOP lawmakers, whose appeal he is seeking to support.

The former Republican governor—who was joined in the filing by PA GOP Leadership Committee Chair Bill McCollum— wrote that the court didn’t have the authority to draw new maps, and argued that justices made a political decision and caused unnecessary tumult.

The junior Thornburgh said in a number of ways, he and his dad don’t actually disagree—specifically, because both think the controversy shouldn’t happen again.

But he said he thinks the new map is ultimately a good thing.

“It has led people to fundamental questions about, how did we get here to begin with?” he said. “Once you come to that conclusion, then you, I think, also come to the conclusion that there’s got to be a better way to do this.”

David Thornburgh heads the government accountability group Committee of Seventy. He’s pushing to take redistricting out of the hands of the legislature, and make the entire process less partisan.

He noted, his dad is coming at the issue from a purely legal perspective.

“In the brief, he’s looking at the more narrow arguments about the intersection between the U.S. Supreme Court and what actually played out here in the state court,” he said. “We’re looking at the whole process stem to stern, and saying we need more public engagement.”

It’s unclear if the court will actually accept Governor Thornburgh’s brief. Justice Samuel Alito initially rejected it for violating the court’s printing rules, and hasn’t yet said whether he will reconsider.