Exactly. There's no enforcement clause for anything but treason.
Where is the “enforcement mechanism” in the Constitution for treason? Article 3 Section 3 defines treason and how one must be convicted of same, but not the “enforcement mechanism” other than the executive branch; and it’s left to Congress to define the punishment required.
PS. There are four federal laws that outline the mechanism for punishing violation of oaths/affirmations of office, listed here: http://foavc.org/01page/Articles/Violation%20of%20Oath%20of%20Office%20and%20Walker%20v%20Members%20of%20Congress.htm