How to enable and disable scripts on a Game Object?

Question

This worked briefly yesterday, I believe I did something to mess this up. All my inputs that I put in are correct; therefor, it must be the code. I want to switch players. While the red cube's script is enabled and can move under the movement script I want the blue cubes movement script to be disabled and vice versus. Can you give me some insight into what I'm doing wrong? Please and thank you!!

using UnityEngine;
using System.Collections;

public class PlayerMovementScript : MonoBehaviour {

    public float speed = 2f;
    public float height = 2f;

    public Component playerMovement;
    public GameObject redCube;
    public GameObject blueCube;

    void Start() 
    {
        var bc = blueCube.GetComponent<PlayerMovementScript>();

        bc.enabled = !bc.enabled;
    }

    // Update is called once per frame
    void Update () 
    {   
        if (Input.GetButton ("Right")) 
        {
            transform.Translate(Vector3.right * speed * Time.deltaTime);
        }

        if (Input.GetButton ("Left")) 
        {
            transform.Translate(Vector3.left * speed * Time.deltaTime);
        }

        if (Input.GetButton ("Jump")) 
        {
            transform.Translate(Vector3.up * height * Time.deltaTime);
        }

        var bc = blueCube.GetComponent<PlayerMovementScript>();
        var rc = redCube.GetComponent<PlayerMovementScript>();

        if (Input.GetButton ("Switch")) 
        {
            bc.enabled = !bc.isActiveAndEnabled;
            rc.enabled = !rc.enabled;
        }
    }   
}

Answer 1

I eliminated the script's start function and just called the components in the update function.

var bc = blueCube.GetComponent<PlayerMovementScript>();
        var rc = redCube.GetComponent<PlayerMovementScript>();

        if (Input.GetButton ("Switch")) 
        {
            bc.enabled = !bc.enabled;
            rc.enabled = !rc.enabled;