CHICAGO (AP) – In the cluttered office where he’s met with some of the nation’s top politicians and preachers, penned rousing speeches and planned civil rights marches, the Rev. Jesse Jackson speaks so softly – and with so little enunciation – that one strains at times to hear him.

At 71, he still keeps a hectic schedule and speaks extemporaneously on everything from voting rights to hostages in Gambia. But the head of one of America’s most prominent families struggles when addressing one thing: the son and heir to Jackson’s political influence who abandoned his congressional seat last week because of mental health problems and two federal investigations into his political dealings.

Sitting in his office – among photographs of mentor Martin Luther King – the elder Jackson’s body tenses, he sighs and his eyes drift off.