Okay ... that is really interesting, and something I hadn't noticed. And it's not the part you think.
... nor shall any State deprive any person of life, liberty, or property, without due process of law; ...
Even if "liberty" here includes the liberty to hold office (which it may not), the law we're talking about is constitutional. It is not a State who would be depriving the liberty, it would be the United States.
The part that is still catching me up, however, is this, just preceding the above:
No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States ..., without due process of law."
If, like in the other clause, the liberty to hold office is a "privilege," does this prohibit States from enforcing this constitutional law? Because when the constitutional law has everything to do with elections, which are run only by the States, no body has jurisdiction to enforce.
If "due process of law" necessarily means "a judicial hearing" (not necessarily a criminal trial), that means that there must be input from a court before someone is disqualified.
So, we have two questions that need answering:
- Is holding office a "privilege ... of citizens"?
- Does due process of law mean "judicial trial"?
Both of those have to be "yes" in order for the disqualification under Section Three to be self-executing (the disqualification being immediate once the described conditions are met). Someone would have to make a legal and binding judgment.
However, if A14 S3 is not self-executing because of this kind of reasoning, then neither are any parts of the Constitution regarding qualification for office. Junior high kids could gain the office of Governor. Arnie could be President.
Even so, the person or group that would make that judgment might arguably be the State process for qualifying people from office, and the judgment could be communicated and recorded by the disqualification itself by that person or group.
Anyway - those bulleted questions above would need to be answered in order for me to go any further. I suspect one or the other of those answers is "no," but I can't really say. The kind of deep legal history study that would be required to answer those two is way beyond what I know.
This is the first time I've been plain stumped by this disqualification thing.