"She says their names."

Hillary Clinton began running a TV advertisement, called "Stand," in the Philadelphia market Tuesday. Narrated by actor Morgan Freeman, the 30-second spot discusses Clinton's support for African American mothers who lost their children to gun violence or while in police custody.

It features Clinton speaking the names of Sandra Bland, who died in police custody after a questionable traffic stop turned abusive, and Trayvon Martin, shot and killed by a vigilante in Florida. There is video of the former secretary of state, senator and first lady meeting with a group of mothers and hugging several of them. The ad goes on to discuss Clinton's advocacy of a bill to end racial profiling while in the Senate, and her support for an end to discriminatory criminal sentencing.

And, Freeman says, Clinton "stands with the president against those who would undo his achievements – just like she's always stood with us."

Clinton's bond with black voters, who also were staunch supporters of former President Bill Clinton, has been perhaps her greatest demographic strength as she contends with Sen. Bernie Sanders for the Democratic presidential nomination. Mrs. Clinton clearly would like a strong turnout from minority supporters in Philadelphia to help her win the April 26 Pennsylvania primary.

The ad is airing as part of a six-figure statewide broadcast and cable buy previously announced by the campaign on Friday.