Who was is that said "consistency is the hobgoblin of small minds?" I disagree with that - I do think consistency is important. But I think sometimes inconsistency is sometimes superficial, and used as a rhetorical device.

For example, with capital punishment and abortion, being "for" one and "against" the other could be described as being inconsistent, but I think it depends on what your principles are. For someone pro-choice and anti-death-penalty, the key issue is a mistrust of government power. For someone pro-life and pro-death-penalty, the principle might be protection of the innocent but not the guilty. I guess the key is thinking through your principles, and most of us just don't do that very often. The funny thing about the term cognitive dissonance is that, according to the theory of cognitive dissonance, we should be motivated to reduce dissonance, and yet, as Lerk points out, we tend to live with it.