The most prominent clue is that Bill Maxwell is playing a turn on his "I Spy" Kelly Robinson fifteen years down a dead-end road, where his Cold War battles have apparently led him to be mired in eroded ruts.
The very opening sequence implies the murder of his long-time black partner.
In fact, the entire series -- from the pilot movie -- onward is a witty investigation of the uses and abuses of power, from the roles and capabilities of women (contrast/compare Connie Sellaca's attorney with Rhonda's confused teenager struggling for esteem) to the limits of American adventurism against the continuing threats of the Cold war. Here is a man of conscience chosen by Higher Powers to right wrong who struggles to be a decent father, lover, friend, and inspire kids by his "ordinary" example.
My favorite episode is "Lilacs, Mr. Maxwell", where Emmy-winning writer Robert Culp reveals in the Season 2 finale the depths and intelligence of the Bill Maxwell character.
Cannell wrote the pilot in an atmosphere of the Iran US Embassy hostage situation and a cultural dearth of idealism. Many viewers saw the red suit comedy and missed the morally ambiguous complexity lying beneath.
