There's been plenty of debate here over whether Trump should be disqualified but I wanted to focus purely on the legal arguments everyone finds most convincing, including one in particular that I came up with which I will lay out below.
First, let's break this down. The legal case comes down to three parts:
1) Does the 14th amendment section 3 apply to Trump?
2) Did Donald Trump engage in insurrection or provide aid and comfort to the enemies thereof?
3) Who and by what process is this decision made?
Part 1 is obvious in my opinion. To argue the office of the presidency is not an office under the United States is absurd on its face, plus this question was already brought up and resolved at the time the amendment was drafted.
Part 2 is a big one but ultimately pointless to debate until the answer to part 3 is resolved.
Part 3 is therefore where I believe the debate here is. So when it comes to who decides let me begin with section 5:
"The Congress shall have the power to enforce, by appropriate legislation, the provisions of this article."
What I'm reading here is that it's Congress's job to determine the proper process by which this issue is resolved, however it appears no such legislation was ever drafted. This in my opinion strengthens the argument that section 3 is "self executing", meaning that it's up to the courts to decide based on the legal challenges it receives. This amendment is therefore no different than adjudicating any other ballot eligibility issue such as whether an aspiring candidate is 35 or an American born citizen. No trial is required in those cases, nor is one required here.
Being that Congress never did appropriate legislation to resolve this, the only option apart from self execution is that the courts don't have the authority to decide either, in which case the answer is that no one gets to decide and section 3 becomes null and void. That outcome is definitionally out of line with the constitution.
But wait...
About two days ago I heard a rebuttal that actually did change my mind and convinced me that Trump should in fact be left in the ballot. It went as follows: Although there is no official process to address section 3, this question was already adjudicated in Congress in Trump's 2nd impeachment trial. It was the exact charge section 3 describes and Trump was aquitted. Therefore the SC has no rightful business stepping in and deciding that their opinion on whether Trump is guilty overrides the very body that section 5 deems as the body with the power to enforce this amendment.
I accepted this argument until thinking it over today. Here is why I believe that argument ultimately fails: First is that the reason Congress used the impeachment process to adjudicate this issue is because that was the only process constitutionally available to them so it wasn't designed to address this specific issue. The Impeachment trial in the Senate is split into two votes, first is conviction requiring a 2/3rds majority which results in removal from office. The second, upon conviction, requires a simple majority resulting in disqualification. The bar for the first vote is intentionally high because the removal of a sitting president is far more disruptive and demoralizing to the country. The second vote has a lower threshold because disqualification is not nearly as disruptive.
So with that in mind, the fact that the Senate voted 57 to 43 when the only issue at play here was disqualification is notable for a number of reasons. First is that disqualification requiring a simple majority was intended for the case where a president commits any action that qualifies as a high crime or misdemeanor. But the charge here is not any high crime or misdemeanor, in fact it is the only high crime that has its own special disqualification clause in the constitution so that right there tells us the threshold here could very easily be thought of differently. And in fact, section 3 lays it out:
"But Congress may by a vote of two-thirds of each House, remove such disability."
In the context of this argument, this clause tells us a lot. First is that the framers of the 14th amendment thought this issue was so important that even if 3/5ths of Congress thought he should be on the ballot, that would not be enough to clear him. The second thing it tells us is that Congress is not actually the intended arbiter if this issue. Section 5 is clearly meant as an override, meaning the case would have been decided by the time it gets to Congress.
So given all of this, here's how I see it; The only two bodies in question that have a constitutional claim to arbitrate this issue nationally is Congress and the SC. The argument that Congress is the arbiter fails in my opinion but even if it doesn't that only hurts Trump. The most favorable answer to Part 3 I asked earlier is therefore that the SC gets to decide Part 2.
From there, is just a question of whether in the opinions of the 9 justices, Trump engaged in insurrection. While I have no confidence they would find that he did, from here is just a matter of facts and logic which I find undeniable.
So what do you think about this? And what arguments for or against his disqualification do you find most convincing.