Muslims do NOT acknowledge the Natural Rights of Man - therefore, a Muslim who swears the Congressional oath of office is lying.
The oath used today has not changed since 1966 and is prescribed in Title 5, Section 3331 of the United States Code. It reads: I, AB, 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. In contrast to the presidential oath, where its used only by tradition, the phrase so help me God has been part of the official oath of office for non-presidential offices since 1862.
BTW - any Muslims who currently occupy the White House also lied when they took their oath of office.