“As a general rule, it is difficult for people in public life to change their minds. There is an immediate rush to portray politicians as ‘flip-floppers’ when they shift position on anything, even if they do so following a careful consideration of an issue rather than a meeting with a pollster. The hecklers will reliably accuse them of lacking the ‘courage of their convictions,’ of being ‘typical politicians,’ even though the typical politician actually tries to change his mind as rarely as possible, to avoid the hecklers.”