GameObject "not defined" when I try to reference across scripts

For a summary with what I'm trying to do, I'm testing a function that will allow me to switch between t$$anonymous$$rd person and first person when I transition to an aiming state. I thought it would be easy because all you really need to do is give it a reference, but then I realized that the aiming state script can't refer directly to unity and needs to pull reference from my main script, otherwise I would get a Null error. Here are my scripts right now:

The reference on my Character Controller Script:

       [Header("Game Objects")]
         public GameObject Player;
         public GameObject fpsCam;
         private void Start()
         {
             TransitionToState(idleState);
         }
 

The function on my aiming state script:

 public override void EnterState(Player_Controller player)
         {
             GameObject fpsCam = GameObject.FindGameObjectWithTag("fpsCam");
     
             fpsCam.SetActive(true);
         }

I figured by now it'd have a point of reference since the gameObject itself is linked to the camera in unity. But when I try to enter the aiming state it tells me that fpsCam is not defined. What am I missing here?