Michelle Obama Goes Sleeveless in Jason Wu at State of the Union Address

In the sea of dark businesses suits and fitted jackets in Republican red or Democratic blue, First Lady Michelle Obama shone at Tuesday night's State of the Union address in a sleeveless oxblood-and-black organza tweed dress by her go-to designer Jason Wu.  Accented with a silver cherry blossom  brooch, the dress is part of Wu's pre-fall 2013 collection, according to style blog Mrs-O.com.  That's the second time Jason Wu dressed the first lady in less than a month—the 30-year-old designer also took credit for the shoulder-baring red gown Obama wore at January's inaugural ball.

"I don't think any designer could ask for any better endorsement," Wu told the Financial Times during New York's Fashion Week on Sunday.

As President Obama  prepared to give his State of the Union address Tuesday night, all eyes (and tweets) were on his wife. Vanity Fair cheekily tweeted that her flower pin -- created by Alexis Bittar, who also designed the elongated brooch she wore at last year's State of the Union speech -- was an homage to Carrie Bradshaw. The Wall Street Journal's Elva Ramirez called her dress's purplish hue "a go-to color for independents" sending the message of "non-partisanship."

Related: Rand Paul Delivers Tea Party Response to State of the Union

The first lady had already made headlines earlier in the day, when her office released the list of people who had been invited to sit with her during Tuesday's speech. Along with Dr. Jill Biden and senior advisor to the president Valerie Jarrett, Apple CEO Tim Cook, "wounded warrior" Sergeant Carlos Evans, and Mars Curiosity Rover flight director Bobak Ferdowsi are among the 24 honored guests, as are Cleopatra Cowley-Pendleton and Nathaniel A. Pendleton Sr., whose teenage daughter, Hadiya Pendleton, was shot and killed on Chicago's south side just a few days after performing at President Obama's inaugural celebration in January.

PHOTOS: Michelle Obama and the Looks that Rocked the Capitol

Tuesday night's appearance was Mrs. Obama's first big fashion opportunity since the inauguration in January, when we were once again reminded why everything that Michelle Obama wears matters. Moments after she arrived for the daytime inauguration ceremony wearing a power-suit-inspired coat and dress, menswear designer Thom Browne became a household name; The New York Times called it a "lightening strike moment" that vaulted Browne "from influential semi-obscurity into the limelight and the American mainstream." Her decision to once again wear a Jason Wu gown to the inaugural ball didn't just put an obscure young designer on the map, it secured his place in fashion history. (After she wore one of his cream-colored creations to President Obama's first inauguration, the New York-based designer's  workshop went from three employees to 30.)

The first lady's State of the Union outfit isn't scrutinized as much as her inaugural choices, but she has used the occasion to make powerful fashion statements before. In 2009, she wore a deep purple sleeveless Narciso Rodriguez dress to the State of the Union speech and, even though she wasn't the first First Lady to accessorize by baring her arms -- in 1963, Jacqueline Kennedy stood out in a sleeveless black sheath dress during President John F. Kennedy's State of the Union address, a stark contrast to the fur-collared crowd surrounding her -- the look took the fashion world aback.

"Oh my God," Cindi Leive, the editor of Glamour magazine told the New York Times soon after. "The First Lady has bare arms in Congress, in February, at night!"

Perhaps because of all the attention focused on her bare arms, the first lady scaled things back in 2010, when she wore a modest, 3/4-sleeve wine-colored Isaac Mizrahi dress, which she paired with a single strand of pearls. In 2011 she kept her arms covered up again, wearing a sleek, pale-gray dress by Rachel Roy. But the shiny, sapphire-blue silk Barbara Tfank dress that she wore last year featured dainty capped sleeves that showed off those famously toned arms.

This year, she went back to her signature sleeveless look in a fashion-forward, fit-and-flare color-block dress by Jason Wu. Though plenty of people raved about the outfit, some viewers thought that the deep red organza tweed flounce dress was too sparkly for the occasion. "Forget FLOTUS' dress designer," Samar Kaukab Ahmad quipped on Twitter. "Justice Ginsburg and her collar are the fashion story of the night."

Also on Shine:

Knockoff of Michelle Obama's Election Night Dress Sells Out in 2 Days

PHOTOS: The First Lady's Best Fashion Moments

Michelle Obama's Style Dream Team

Will this help YOU amplify your style?