Romney never appeared motivated by a passionate zeal to become President, but this is common of most present political players. I watch Fox and MSNBC and CNN and the politicians are flat -- they go through the motions. Obama has had a few moments of passion, but mostly he's just saying the words moving across the monitor. I don't hear any politicans passionately present ideas that are alive -- there's a lot of policy talk and platitudes but nothing close to the political poetry of a Reagan or JFK.
I suspect the grind and baseness of modern politics kills any political spirit that might be there in the beginning when a person decides to serve the public. Plus, modern media is so vicious, superficial and dishonest, it's hard, I imagine, to let yourself go and be natural in interviews. When political spin is placed on each word, politicians become careful and bland.
Aside from the great benefits of being a Senator or President, I can't think of much else that emanates from DC which is inspiring. The public has a very low opinion on Congress, and members of Congress don't do much to improve their image. It appears to me that government is in decline, caught up in a system they don't even try to fix anymore, just going through the motions, taking what they can with one eye on a lucrative way out when they see their careers coming to an end.