BERKELEY (CBS/AP) — The two lawyers who teamed up to defeat California’s same-sex marriage urged future members of their profession to take a lesson from their unlikely alliance.

Theodore Olson and David Boies were the keynote speakers at UC Berkeley School of Law’s graduation ceremony on Saturday.

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Before they joined forces in 2009 to challenge California’s Proposition 8, they were known for their respectively fierce advocacy in Bush v. Gore, the disputed 2000 presidential election case eventually won by Olson on behalf of George Bush.

Olson said lawyers need to respect their opponents if they want to prevail.

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The Berkeley law alumni told the graduates he recognized Boies’ poise and talent even when they were rivals.

Boies agreed, saying their partnership was proof that “if you can find common ground, you can accomplish great things.”

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