Some former Justice Department officials who served under Donald Trump during his first term fear that the Supreme Court’s recent immunity ruling will make it easier for him to use the department against his enemies if he is re-elected president. Other ex-officials downplayed the impact of the ruling — or endorsed it. Two former Justice Department officials, who spoke on condition of anonymity, said the ruling would embolden Trump. They said it would give Trump cover to improperly pressure the Justice Department for his own political benefit — to prosecute an enemy or go easy on an ally — by...