Kamala Harris slams Trump for killing the bipartisan border deal. Plus, how a new Georgia election board rule could impact November. Also, what the incident at Arlington National Cemetery show us about Trump. And West Virginia's oldest and youngest delegates call out Trump at the DNC. Keith Ellison, Sara Tindall Ghazal, Ruth Ben-Ghiat, Jean Evansmore, and Kathryn Prather join Ali Velshi.