Harris faces uphill climb amid questions about who she is

Sen. Kamala D. Harris had everything she needed to make her pitch. Big yellow cutout letters spelled “Justice for the People” on the stage behind her. White folding chairs splayed out ahead of her, most of them filled, and their occupants seemed happy to see her. Nothing smelled of a flailing campaign.

“I’m spending a lot of time in what I am now thinking of and considering to be my second home, South Carolina,” Harris told the crowd, drawing some nods of approval.

“I’m also spending a lot of time...