The insurrectionist ban is only for people who participated in the civil war
My guess is this one or close to it. It's going to be an originalist interpretation of something like the definition of "insurrectionist" or "armed" and include a phrase like "the founding fathers didn't envision...". The reasoning might be some bad esoteric case law from the 1800's that defines insurrectionists as carrying literal muskets and pitchforks therefore Trump is not one.
That and they may just stall for time until after the election and claim they couldn't interrupt the democratic process term limits. Either way, Trump's chosen judges are about to have their decisive moment.
My hope is that they just ban him because he no longer has leverage after appointing them, but I am not sure if that would be an even worse indictment of their suitability as Supreme Court judges...
Supreme Court will take up Trump’s eligibility to run for president (www.politico.com)