I may be slaughtered here for saying so, but I can't see J6 as a "coup".
There's too much of an underpants gnome quality, with no clear path leading from "unruly mob pushed its way into the Capitol" to "Trump is inaugurated with the acceptance of (at least a majority of) the country".
It follows much more logically if we model it as an irrational rioting mob. This doesn't make it right, but it moves the suspicion from "subverting democracy" to (simply?) inciting a riot.
It was an irrational rioting mob sent by Trump and allowed to continue for hours while he sat on his rear hoping they would be successful in forceably preventing the transfer of power. He and his co-conspirators knew exactly what they were doing. The insurrectionists that he told to stand back and stand by implemented stack formations to breach the capitol.
There's too much of an underpants gnome quality, with no clear path leading from "unruly mob pushed its way into the Capitol" to "Trump is inaugurated with the acceptance of (at least a majority of) the country".
It follows much more logically if we model it as an irrational rioting mob. This doesn't make it right, but it moves the suspicion from "subverting democracy" to (simply?) inciting a riot.