14th Amendment

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.

Pascrell issued a statement to House leaders publicly asking them to exercise this clause of the Constitution.

Source: House Democrat invokes Civil War amendment that would prevent 126 Republicans from being seated in Congress