The singer debuted the ballad, titled 'Bring It On Home', at a fundraiser for the Democrat at New York's Plaza Hotel on June 14, reports ABC.
Carey, who was a huge supporter of Obama's initial presidential campaign, took to Twitter after Thursday's event to share her excitement with fans.
"Just finished performing Hero, We Belong Together and BRING IT ON HOME - a song I wrote especially for the event," she posted.
She later shared a picture of herself in the Vera Wang gown she wore for the appearance.
"Listening to Bring It On Home, wishing I could put this out!" she added, before tweeting possible lyrics from the track: "Strength is what we need and love keeps us alive..."
Carey is currently working on a new album and shared pictures of herself in the studio earlier this year.
Watch a video of Mariah Carey and Jermaine Dupri talking about their studio time together below: