The Senate as a symbol
Throughout the book (just because of which examples Kennedy selects) the Senate itself can be viewed as a symbol for public opinion. Because the Senate is divided in half, it serves as a helpful reminder that American politics has always been about the synthesis of two points of view. Also, because Kennedy tends to only select issues that offended both parties, the Senate can be seen as an example for the majority points of view, and that means that his version of courage is defined by finding a third answer. In his examples, there is a conservative answer, a progressive answer, and often, a third hybrid answer. He tends to support hybrid answers, although he gives examples of when each of the other kinds are brave too.
Adams as an allegory for progress
One of the times that Kennedy praises someone for their progressiveness (despite public opinion) is the case of John Quincy Adams. Adams moved forward in time, in a way, because he forecasted the downfall of the Federalist Party and chose to move into a new, more independent kind of politique. That means that his story can be seen as an allegory for when progress is the ethical choice.
Sam Houston as an example for loyalty
If Adams is an example for progressivism, then Houston is an example of true conservatism, even though the South seems more conservative in nature. The trick here is to remember that the movement to secede from the Union was actually a very liberal, progressive kind of idea (to uproot the entire history of the nation, basically). It's Houston's silent rejection of the Confederacy that lands him his spot in Kennedy's hall of fame.
The motif of slavery and war
Daniel Webster, Thomas Hart Benton, and Sam Houston are examples of this motif, because all three of their instances of bravery involve the difficult subject of slavery and the outbreak of Civil War following the secession of the South. The motif helps to enforce the underlying, unspoken argument that politicians are often asked to respond to unbelievably serious issues, and that finding true justice in light of public opinion can be very confusing and difficult. Kennedy praises these men for standing firm through the maelstrom of public argument.
Nazi Trials as a symbol
When Kennedy ends his book with his praise of Robert Taft, it's his way of saying that he views Taft's bravery as the ultimate kind of courage, because Taft not only spoke out in defense of his beliefs, he did it even when he knew his political career could be ended. He knew that his opponents would instantly spin his comments into Nazi sympathies, and indeed, his outspokenness did cost him the presidency. So, he is a symbol, and his archetypal value is his undeniable courage to say what he believes, even when that means defending the enemy's rights.
