The history is interesting. Jefferson Davis's case never went to trial, while Trump's four criminal cases have gone to trial. J6 was a shocking event, but pales in comparison to the Civil War. The USSC could decide "engaged in insurrection" in the 14th amendment is something similar to the Civil War.

The USSC will decide and then rationalize, and so the reasoning is unimportant, as it will change in the next case. The USSC will decide based on its self-interests, and I don't see anything that is worth the price of intervening in this presidential election. They might intervene if they thought Trump's threat of dictatorship was real, but that would be an act of courage that is unlikely with this USSC that is afraid of even adopting an effective ethics code.

This could be one for the history books. One possible scenario is: The Senate failed to convict out of fear for the lives of their families. The Supreme Court fails to uphold the U.S. Constitution out of fear of losing their money. The voters fail because of broadcast lies. The U.S. democracy fails in this scenario's ending, with Putin celebrating and taking back Alaska.

More likely is that the U.S. court system will find Trump guilty, and the voters will reelect Biden. Trump is truly a weak candidate (found liable for sexual assault and fraud), and the economy under Biden's leadership is booming.

Brief Of Amici Curiae American Historians In Support Of Respondents
"Obstacles to prosecuting Davis had made it increasingly likely that he would not be convicted on treason charges, thus underscoring the need for Section Three... For decades, Jefferson Davis stood as the cautionary tale through which Congress and the public understood Section Three. No danger better illustrated the peril the nation would have faced without Section Three than the prospect of the leader of an insurrection running for President."
supremecourt.gov: PDF document