I think it's worth pondering the purpose of inauguration oaths.
The whole point of an oath is to increase the credibility of a promise. The oath-taker is essentially calling judgment down upon him/herself if the promise isn't kept. When the oath-taker is considered to be sincere in such an oath, it generally adds weight to the promise being made. If the oath-taker doesn't believe in a higher power, the oath is pointless both to the one doing the promising and to the one being promised.
In this light, swearing on the Constitution (as the petition demands) is even more pointless, regardless of one's belief system -- what does "I swear by the Constitution that I will obey the Constitution" even mean?
|Image source: Bizarro|
At one time, the inauguration oath served a real purpose in a culture where the moral value system of Christianity served as an actual constraint on the behavior of the citizenry and (in many cases) public officials. Now that Christianity is being systematically purged from the culture, even pro forma declarations of religious sentiment among public officials are becoming less common.
So, again: is there any point to inauguration oaths any more? It's not like most oath-takers are actually sincere in the affirmations being made (or fear any repercussions of violating those affirmations), so why undergo the ritual in the first place?