"With exceptions so rare that they are regarded as miracles and freaks of nature, successful democratic politicians are insecure and intimidated men. They advance politically only as they placate, appease, bribe, seduce, bamboozle, or otherwise manage to manipulate the demanding and threatening elements in their constituencies. The decisive consideration is not whether the proposition is good but whether it is popular—not whether it will work well and prove itself but whether the active talking constituents like it immediately."

This quotation, from journalist and political theorist Walter Lippmann, summarizes the negative view of the politician, such that exceptions to this category are "miracles."What characterizes this negative view, Lippmann maintains, is politicians' dependency on the wills of their constituents over the merit of pieces of legislation or policy. This sentiment has great significance in Profiles in Courage.

"These, then, are some of the pressures which confront a man of conscience. He cannot ignore the pressure groups, his constituents, his party, the comradeship of his colleagues, the needs of his family, his own pride in office, the necessity for compromise and the importance of remaining in office. He must judge for himself which path to choose, which step will most help or hinder the ideas to which he is committed. He realizes that once he begins to weigh each issue in terms of his chance for re-election, once he begins to compromise away his principles on one issue after another for fear that to do otherwise would halt his career and prevent future fights for principle, then he has lost the very freedom of conscience which justifies his continuance in office. But to decide at which and on which issue he will risk his career is a difficult and soul-searching decision."

This quotation explains the conflict that underlies the work of a senator. In the end, a senator has to honor his or her conscience. However, Kennedy states first that a senator cannot simply ignore external influences and that these external influences are as much a part of the reality of public life as a senator’s own personal principles. Kennedy adds that every issue presents a chance for compromise. Such compromise can aid one's career yet erode one's principles.

"Whatever their differences, the American politicians whose stories are here retold [share] one heroic quality—courage. In the pages that follow, I have attempted to set forth their lives—the ideals they lived for and the principles they fought for, their virtues, and their sins, their dreams and their disillusionments, the praise they earned and the abuse they endured. All this may be set down on the printed page. It is ours to write about, it is ours to read about. But there was in the lives of each of these men something that it is difficult for the printed page to capture—and yet something that has reached the homes and enriched the heritage of every citizen in every part of the land."

This quote illustrates Kennedy's purpose in writing Profiles in Courage. Kennedy believes that courage is a heroic quality, one which every American should realize in their own lives. The lives of senators, in Kennedy's view, should serve as an example for all Americans. Kennedy notes that these senators are not perfect, and their lives are marked with many faults, but nevertheless their political careers contain moments that can serve as inspiration for citizens.