The primary authority for expelling members of Congress who supported the insurrection is Section 3 of the Fourteenth Amendment to the Constitution:

No person shall be a Senator or Representative in Congress, or elector of President and Vice President, or hold any office, civil or military, under the United States, or under any state, who, having previously taken an oath, as a member of Congress, or as an officer of the United States, or as a member of any state legislature, or as an executive or judicial officer of any state, to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same, or given aid or comfort to the enemies thereof. But Congress may by a vote of two-thirds of each House, remove such disability.

Unfortunately, Congress exercised the option to “remove such disability” for those involved in the Confederate insurrection. The result was the end of Reconstruction and the beginning of a siege of terror on African Americans which has not ceased. That is why we must not make the same mistake today.

As I have argued, if the same standards were applied to the current insurrectionists as had been applied to those on the Left, especially those of color, there would be no doubt as to their conviction.