President Biden will deliver a commencement speech to the graduates of Morehouse College on Sunday, an appearance that will put him directly in front of 500-plus young men who represent a slice of the electorate that is drifting away from him and toward his challenger, former President Donald J. Trump.

The commencement address at an all-male, historically Black college in Georgia, a state Mr. Biden flipped by a narrow margin four years ago, will give the president a chance to draw a character…