 Party co-chair Lara Trump delighted the delegates recounting her father-in-law's fist pump Saturday after a would-be assassin's bullet grazed his head. If Donald Trump has shown us anything, it's that when it feels impossible to keep going, those are the times we must keep going. On Wednesday night, vice presidential candidate J.D. Vance will introduce himself to the delegates as the night's main speaker. This is ABC News.