The well-respected legal authorities J. Michael Luttig and Laurence Tribe (the former a conservative, the latter a liberal) have argued that this use of the amendment is legally valid, and an attempt to use it has been put forward in Michigan. But Trump hasn't been charged with, let alone convicted of, insurrection, and I don't think these challenges will hold up in court while that is the case. Luttig and Tribe have argued that this clause of the Constitution is "self-executing," because when it originally went into effect, it wasn't difficult to tell who had participated in the Civil War and should therefore be excluded from office. But a lot of people refuse to see Trump's attack on Congress as an insurrection, so any such claim would have to be hashed out in court. None of the people prosecuting Trump charged him with insurrection, probably because it's more difficult to legally prove than his other crimes, so I don't see this effort going anywhere.Section 3. 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.
The best we can expect is for Trump to go into November 2024 as a convicted felon, appear on the ballot in all 50 states, lose overwhelmingly, and rot in prison for the rest of his miserable life. Letting him run is very hazardous; if he does win, he will try his damnedest to tear down every institution that restrained him during his first term, which probably means either the collapse of American democracy or a second civil war. But I don't think we have a choice.