President Biden invoked scripture and lessons from his own tragic past on Sunday in a commencement address to hundreds of young Black men at Morehouse College, saying he believes there are “extremist forces aligned against the meaning and message” of the prestigious institution.

Mr. Biden’s speech, delivered at the historically Black men’s college in Atlanta, put him directly in front of hundreds who represent a slice of the electorate that is drifting away from him over the war in…