Fresh off speaking at the National Rifle Association convention held three days after 21 people were gunned down in a Texas grade school, Sen. Ted Cruz was confronted by a frustrated citizen in a Houston-area restaurant Friday. Video being shared on social media by the group Indivisible Houston shows an apparent constituent first posing for a photo with Cruz, then engaging him in a seemingly one-sided debate. The man seemed to want an answer as to why Cruz, who receives considerable financial support from pro-gun groups, would speak at a convention celebrating firearms in the wake of Tuesday’s…