Just to be clear, the only thing that Udall and Wyden are actually sworn to is this oath:
"I do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take this obligation freely, without any mental reservation or purpose of evasion; and that I will well and faithfully discharge the duties of the office on which I am about to enter: So help me God."
I am just curious, what is the difference, in relation to that oath, between "swear" and "affirm" (under which circumstance would one be affirming and not swearing and vice-versa)?
If permitted, one might 'affirm' if one's religious belief prohibits 'swearing oaths': "But above all things, my brethren, swear not, neither by heaven, neither by the earth, neither by any other oath: but let your yea be yea; and your nay, nay; lest ye fall into condemnation."
I'm nonreligious, but agree with this position, as the alternative would imply that lying should be expected in all cases where no oath is sworn. Here's one small, specific, interesting piece of the history of offering an alternative: http://www.northcarolinahistory.org/commentary/161/entry
It turns out you're half right. I knew congressmen didn't have to undergo security clearances. But it turns out that starting in the 104th congress (1997-1999), they are required to swear a secrecy oath.
I still think the oath to the constitution is far more important to the integrity of our country, but I was wrong that they swore no other oath.
"I do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take this obligation freely, without any mental reservation or purpose of evasion; and that I will well and faithfully discharge the duties of the office on which I am about to enter: So help me God."