Former President Donald Trump is set to return to the site where he nearly lost his life in July, holding a rally Saturday that his campaign and allies have hyped up as one of the biggest opportunities to boost his candidacy in the final weeks of the presidential race.

Trump’s rally in Butler, Pennsylvania — where he was shot in the ear by a would-be assassin, who killed a rallygoer and injured others — will give him a spotlight for one of his rallies that has been more difficult for…