Former first daughter Chelsea Clinton will narrate a video tribute to her mother, Sen. Hillary Rodham Clinton (D-N.Y.), before the onetime presidential hopeful takes the stage tonight to deliver the headline speech at the Democratic National Convention in Denver.

Chelsea Clinton was a near-constant presence on the campaign trail during the lengthy Democratic primary, which concluded unsuccessfully for the New York Senator in early June. She often introduced her mother on the stump and served as one of her more forceful advocates over the last two years.

Sen. Clinton is expected to make a call for unity tonight before thousands at the Pepsi Center in Denver. Her performance is viewed as critical to helping Sen. Barack Obama (D-Ill.) shore up Clinton’s former primary backers as he heads into the November election.