Stupid voters is not a justification for a coup. Only the absence of elections can be. This is the situation our founding fathers found themselves in.
Again, who would you have installed as our new dictator?
Your question is assuming the situation proceeds as you dictate. That is not necessarily the case.
The military can impose martial law until elections can be held.
There are plenty of “reasons” for a “coup”, as certainly as there are many reasons for a “civil war” or a “revolutionary war”.
Get your head on straight.