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 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.