James Q. Wilson, Negro Politics: The Search for Leadership (The Free Press, 1960, 1965, 1967; Octagon Books, 1980).

“In his 1960 book, Negro Politics, [Wilson] compared two diverse styles of politics of the most prominent black congressmen of the day, William Dawson and Adam Clayton Powell Jr. Mr. Dawson, loyal to Chicago Mayor Richard J. Daley, was a classic machine politician who attracted low-income voters by distributing material favors controlled by the machine — jobs, connections, economic benefits — while assiduously avoiding more controversial, policy-oriented appeals that might divide his constituency and displease ideologically diverse colleagues. Mr. Powell, from New York City, was the exact opposite: a flamboyant firebrand, he often played the race card to win re-election but was isolated in Congress and accomplished little programmatically. Mr. Wilson’s analysis of the relationship between different organizational-political styles and outcomes helps explain, among other things, the challenges that minority politicians everywhere face today.”
Peter H. Schuck (2012)