WASHINGTON — People who crossed paths with Rob Porter in Harvard classrooms or the hallways of Capitol Hill describe him in glowing terms: He was articulate enough to be secretary of state. Intelligent enough to be a Supreme Court justice. Driven enough to be president.

Until Mr. Porter resigned as a White House aide amid domestic abuse accusations, plunging the Trump administration into a scandal over the vetting of West Wing hires, most were certain he would have his pick of positions.

Described as charismatic, intense and privileged, Mr. Porter, the son of Roger B. Porter, a Harvard professor and a former domestic policy adviser to President George Bush, spent years building on his pedigree. He grew up Mormon in a family with close ties to the elite Mormon enclave of Belmont, Mass., collected degrees from Harvard and Oxford University and amassed prestigious job titles.

Though many described him as composed and calm, others in his ultracompetitive workplaces described him as tightly wound, revealing occasional glimpses of how angry he could become, particularly if anyone got in his way. A former White House official said the temper flare-ups left him with the sense that Mr. Porter was more volatile and troubled than his clean-cut image let on.