As Donald Trump waits to see if a Manhattan grand jury will choose to indict him this week, a prospect that he is encouraging his supporters to protest, he is also preparing to hold the first major rally of his presidential campaign in a city that was famously the site of a deadly standoff between an anti-government cult and federal law enforcement. Thirty years ago next month, 86 people died amid a disastrous siege at the Branch Davidian compound in Waco, Texas.