Battery flat as hell or starter is shot/disconnected.
On a late '80s RRC, before the intro of concealed hinge in '89 MY the starter has a relay on the bulhead behind the washer bottle, next but one to the inside IIRC.
This relay, excited by the ignition switch, in turn switches battery power to the piggy-back solenoid on the starter. The solenoid earths via the motor so that the motor turns slowly until the gears engage fully, this helps the gear engage. When the solenoid hits it's furthest travel it also switches full battery power to the motor so that it runs full speed.
So, the click is possibly the relay not the solenoid, the solenoid click is heavier and should be accompanied by the motor running slowly unless the starter engages fully, or as stated the starter is stuck partially engaged with the flywheel.
You can try tapping the starter or rocking the engine via the transmission to try and free a stuck starter.