20,000-Plus Turn Out for Obama Rally with Katy Perry in Milwaukee

Katy Perry Obama Rally Nov 3 - H 2012

Making her third appearance on the campaign trail Saturday, the pop star performed a mini-concert wearing a blue dress with the president's reelection slogan "Forward."

An estimated 20,000 people turned out Saturday In Milwaukee for an Obama rally, featuring a mini-concert by Katy Perry, who donned a tight blue dress with the president's reelection slogan "Forward."

Perry opened her set at the Delta Center with Al Green's song, Let's Stay Together, according to the Milwaukee Journal Sentinel. She then sang Teenage Dream and Part of Me and Wide Awake.

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In between songs, Perry urged members of the audience to donate to the Red Cross to help the victims of superstorm Sandy.

"Let's send them some love today," Perry said. "We care about America, don't we. We care about our people. We're a huge family, a huge family."

She also urged people to vote.

"If you're over 18, and you have a real cool outfit and you wear it on Tuesday, you tweet me and I'll retweet it," she told the crowd.

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Perry then launched into the song Firework. Behind her, a large screen flashed photos of Barack Obama, his wife Michelle, as well as former President Bill Clinton, according to the Journal Sentinel.

Saturday marked the singer's third appearance on the campaign trail for Obama. She's consistently been one of the president's most popular rally performers. More than 13,000 turned out to see Obama and Perry in Las Vegas last month. At that show, the singer donned a tight white dress imprinted with a giant ballot. At a concert fundraiser in Los Angeles, the pop star wore a red, white and blue cape and a Statue of Liberty outfit. Perry designs the Obama dresses herself, then styles them with her team.

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Obama took the stage following Perry's performance in Milwaukee. He told the crowd: "I just have to say Katy has been working so hard these last couple of weeks, and I'm so grateful to her."

Obama has called on celebrities to help get out the vote in the final days of the campaign.

In addition to Perry, Bruce Springsteen, Jay-Z, John Mellencamp, Dave Matthews, will.i.am,  Jason Mraz, Stevie Wonder and Marc Anthony are also making appearances in the swing states.