The 32-year-old Grammy winner has signed on to play a charismatic young politician running for Congress against the conservative uncle of Teddy (Trevor Donovan). Her character, Marissa Jackson-Lewis, is described as a cross between Hillary Clinton and President Barack Obama, according to TVLine. Marissa hires Silver (Jessica Stroup) to make a campaign video to boost the youth vote.
The singer-actress is best known to TV fans as Moesha from the long-running UPN sitcom of the same name. She also guest-starred in four episodes of Drop Dead Diva earlier this year and competed on the 11th season of ABC's Dancing with the Stars.
Season 4 of 90210 premieres on Tuesday, Sept. 13 at 9/8c.