Vikings punter Chris Kluwe, one of the NFL's most politically outspoken players, is joining the gay marriage cause as it heads to the Supreme Court this spring.

Kluwe and Baltimore Ravens linebacker Brendon Ayanbadejo filed an amicus brief to the high court in February, arguing that California's ban on gay marriage is unconstitutional and that professional athletes have an important role to play in promoting tolerance.

The two have worked together before; Kluwe came to Ayanbadejo's defense last August after the linebacker donated a pair of Ravens tickets to a gay marriage fundraiser and was rebuked by Maryland state delegate Emmett C. Burns, who told Ayanbadejo to stick to football.

Kluwe responded on Ayanbadejo's behalf in a strongly worded open letter to Burns on Deadspin's website. Both Kluwe and Ayanbadejo spoke out in favor of same-sex marriage leading up to last November's elections, during which Maryland voters approved gay marriage and Minnesota residents voted down a constitutional amendment that would have limited marriage to heterosexual couples.
Now, they have spoken out about a month before the Supreme Court hears Hollingsworth v. Perry, which could have major ramifications for same-sex marriage across the country.

In February 2012, the Ninth Circuit Court of Appeals upheld a district court ruling that California's gay marriage ban violated the 14th Amendment. The Supreme Court is scheduled to hear oral arguments on March 26.