The Court botched the legal reasoning and relied heavily on dubious policy arguments.
Trump deserved to lose on all these points, and the Colorado Supreme Court correctly rejected his arguments on them. But I think he did have a plausible argument on the issue of whether his involvement in the Jan. 6 attack was extensive enough to qualify as “engaging” in insurrection. At the very least, he had a better argument there than on self-execution. The Court’s resolution of the latter issue is based on badly flawed reasoning and relies heavily on dubious policy arguments invoking the overblown danger of a “patchwork” of conflicting state resolutions of Section 3 issues. The Court’s venture into policy was also indefensibly one-sided, failing to consider the practical dangers of effectively neutering Section 3 with respect to candidates for federal office and holders of such positions.
But who defines an insurrection? Republicans accuse Biden of insurrection because immigrants exist. They'd use that to justify removing him from the ballot. Without definitive language, Republicans will always act in a dishonest manner.
The Republicans could accuse Biden of being under 35. They'd have a hard time convincing anyone, but some corrupt judge in Alabama might toss him anyway.
The SC has already said states can decide that question.