Basic winning defense: A President cannot “insurrect” against his own government, which he heads.
That’s actually not a strong defense. The president is not the government or even the head of the government , he is the head of one third of the government. If the president decided to disband Congress and the judiciary by force, that would certainly qualify as an insurrection. So yes, the president could be guilty of insurrection. That’s not the case here, but to try to say the president could not be guilty of insurrection against his own government is a losing argument.