The Colorado court got this issue right. The case is now likely headed to the US Supreme Court. (ILYA SOMIN | 12.19.2023, Volokh Conspiracy)
The per curiam majority opinion does an excellent job of handling all the major issues at stake: whether the January 6 attack was an insurrection, whether Trump’s role in it was extensive enough to qualify as engagement, whether the president is an “officer of the United States,” and whether Section 3 is “self-executing” (that is, whether state governments and courts can enforce it in the absence of specialized congressional legislation). In the process, the justices partly affirmed and partly overruled the trial court decision, which held that Trump did indeed engage in insurrection, but let him off the hook on the badly flawed ground that Section 3 doesn’t apply to the president.
The case is now likely headed to the US Supreme Court. The justices may well hear it on an accelerated schedule, so as to resolve the case before we go too far into the GOP primary process. The Colorado Court has stayed its decision until at least January 4, to allow time for appeals to the US Supreme Court.
The 4-3 vote is not as close as it looks. Two of the three dissenting justices did so on the ground that Colorado state election law doesn’t give the state courts the authority to decide Section 3 issues. They did not endorse any of the federal constitutional arguments on Trump’s side. And these state statutory issues probably cannot be reviewed by the US Supreme Court, because state supreme courts are the final arbiters of the meaning of state law (with a few exceptions that do not apply here).
I think it’s fairly obvious that the January 6 attack on the Capitol amounts to an insurrection, and the Colorado justices also concluded this is not a close issue…