Long known for his improvised and volatile stage performances‚ former President Donald J. Trump now tends to finish his rallies on a solemn note. Soft‚ reflective music fills the venue as a hush falls over the crowd. Mr. Trump’s tone turns reverent and somber‚ prompting some supporters to bow their heads or close their eyes. Others raise open palms in the air or murmur as if in prayer. In this moment‚ Mr. Trump’s audience is his congregation‚ and the former president their pastor as he...