Arnold Schwarzenegger says the push to change the redistricting process is a lot like bodybuilding.

It's an unusual comparison, and it's also unusual to see the former California governor, movie star and world champion bodybuilder wade into Wisconsin's redistricting challenge.

Schwarzenegger is one of several prominent national Republicans who are supporting the U.S. Supreme Court case challenging Wisconsin's Republican-drawn legislative map, known as Gill vs. Whitford.

He got involved with the issue as governor, when he pushed successfully for a commission to draw California's district lines, with the idea being that politicians should not draw their own political boundaries.

Schwarzenegger said it took time to sway public opinion.

"You've got to get the conversation going," Schwarzenegger said in a conference call with reporters. "I remember with bodybuilding it was the same thing. No one knew what the hell bodybuilding was, and then we had to really promote it and talk and talk and talk, and give speeches and write books … and then eventually it became popular and now everyone does it."

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Schwarzenegger said without changes to redistricting, the party in power will always seek an edge.

"When Republicans have the power, they gerrymander, like in Wisconsin, which gave us Gill vs. Whitford," Schwarzenegger said. "And when Democrats have the power they gerrymander, like in Maryland or Illinois."

In addition to Schwarzenegger, Republicans U.S. Sen. John McCain and Ohio Gov. John Kasich have signed on to legal briefs in support of a legal standard that courts could use to strike down legislative maps as partisan gerrymanders.

A federal court struck down Wisconsin's map late last year and ordered a new map drawn by November 2017.

The U.S. Supreme Court put that decision on hold while it considers an appeal of the decision. Justices scheduled oral arguments in the landmark case for Oct. 3.