It has been the official position of the DOJ for more than half -a-century that they cannot indict a sitting president for, among other reasons, it would essentially decapitate the executive branch; moreover, those involved in such a process (grand jury, prosecutor, judge, etc.) ought not hold such power over a president who is elected by the entire nation.

I have argued, in part, that the immunity issue flows from that -- that is, if a president knows he can be indicted for his officials acts by a subsequent administration, after he leaves office, it would cripple his ability to exercise his duties.  He would have to wonder whether a quick decision or a difficult decision or a decision that seemed right at the time would be subjected to criminal scrutiny after the fact, and after he had left office.  The presidency would be gravely damaged.

This would have fundamentally altered separation of powers, greatly weakening the office of the presidency, and effectively amend the Constitution by criminal prosecution.  No longer would there be the balance and division among the branches that the Framers worked so hard to enshrine.

The January 6 case was built on 3-statutes having nothing to do with the events of January 6.  And nothing to do with insurrection or sedition.  The statutes have never been applied in the way that Smith applied them.