An occasional look at the celebrities with a cause who flock to Washington in hopes of, you know, changing stuff. Tuesday’s visitor: Jada Pinkett Smith.  Jada Pinkett Smith and Will Smith at the State Department. (Cliff Owen/AP) Venue: State Department’s diplomatic rooms.  Occasion: Release of a State report on slavery, prostitution and forced labor around the world.  Bona fides: Actress, mom of tweener stars Jaden and Willow Smith, who urged her into advocacy after seeing the Kony 2012 video and telling her, “Mommy, did you know that there are girls that are being trafficked my age?”  Support: Hillary Clinton, superstar husband Will Smith.who made of point of keeping in the background, spouse-of style.  How she looked: Elegant in a cream blouse, matching slacks, high heels.  What about Will?: Hey, remember, this wasn’t about him! But since you ask — navy suit, no tie, canvas loafers.  What she did: Unlike most celebvocates, Smith did not take the mic, leaving the speechifying to Clinton and speaking individually to reporters later.  Contribution to the cause: A music video, directed by fellow movie star Salma Hayek, in which Smith sings a Spanish tune, “Nada,” while writhing on a mattress — completely naked! — interspersed with scenes of a bad boyfriend selling his nice girlfriend into slavery.  What’s that about?: The Spanish lyrics are “a statement that one woman is every woman. . . we’re all in this together.” The nudity was Hayek’s idea, she said. “We believe that part of combating this issue, as women, we have to reclaim ourselves.”  Video: Jada Pinkett Smith, “Nada”  Read about other Celebvocates in The Reliable Source  Also in The Reliable Source:  Quoted: Rielle Hunter on her current relationship status with John Edwards  In other news: Alec Baldwin vs. paparazzi heats up  Hey, isn’t that. . . ?: Harry Connick Jr.  What a Journey! Michaele Salahi and Neal Schon walk red carpet at Silverdocs, bail out early  Rielle Hunter tells all — again! Grading the revelations in new book by John Edwards mistress  Sewall-Belmont House supporters split over award for Laura Bush
A newcomer to the cause, the actress appeared with Hillary Clinton at the State Department and released a provocative music video.