He has realised that claiming a security issue is his route to maximum control.
Tariffs? Security issue.
Mexican infants? Security issue.
Moslems? Security issue.
And Congress and the Supreme Court are now populated with the sorts of folks who will let him game the system in this way.
The only thing that isn't a security issue? Russian interference in US elections.
I just hope the country can split peacefully as what the US has ain't a democracy any more.