Chad Griffin, the president of the Human Rights Campaign (HRC), believes the Supreme Court will side with proponents of gay marriage.

In an appearance on MSNBC's Hardball, Griffin sounded confident that the case challenging California's marriage ban, which he helped bring to the high court in his former role as president of the American Foundation for Equal Rights (AFER), would emerge victorious.

The case, Hollingsworth v. Perry, challenges the state's 2008 voter-approved constitutional amendment defining marriage as a heterosexual union. The measure was put in place after the California Supreme Court legalized marriage for gay and lesbian couples.

A federal district court judge declared the measure unconstitutional and an appeals court upheld that decision.

“We made the case in court, [lawyers] Ted Olson and David Boies made the case in court, that in this country we don't deny our citizens a fundamental right,” Griffin said. “And the Supreme Court has called marriage a fundamental right no less than 14 times in the history of this country.”

“And I'm optimistic that once this court does hear this case and the DOMA case that they are going to come down on the side of freedom, liberty and equality, just as they have so many times in our nation's past,” he added.

The Supreme Court is expected to hear arguments in March and deliver a ruling in June.