In the late spring of 1968, when I was 26, I helped organize Robert F. Kennedy’s presidential campaign in the Bronx. I rented a storefront headquarters, recruited a team of volunteers, and held a launch event at the old Concourse Plaza Hotel—all to prepare for the candidate’s expected appearance in New York following his victory in California. That, tragically, wasn’t to be. Instead, I took my turn in the honor guard that surrounded the senator’s casket throughout the night in St. Patrick’s Cathedral, and attended his funeral June 8.

When...