When a leader loses part of his authority?

Thanks

Well... may be when he- she fail to achieve goal-s , when he-she loses his-her followers, when the top management see that this leader does not deserve this authority since he-she does not use it as it expected .

Thank you. When leader defeated from competitor or or fail to achieve goal. 

Thanks for invitation,

When he are badly using this authority and deviate or fail to achieve targets.

He must know the cause of the loss. If to return to its conduct by what is weak it must change it if not it must be studied the cause and find the solution

Thanks for invitation

Mistakes are the reason but the main one is Loss of the ability to achieve the goals (Mr. Omar post) which lose a lot of the leader powers and his status with the organization's leadership and his subordinates. But if the leader have true  qualities of the leadership  he is able to return after take advantage of the above. 

from my opinion he lose part of control, but he stil can handle it.

If a leader who has a formal decision-making authority over a matter, by definition of his position, flees the decision, seeks shelter, fears liability on this issue, loses part of his authority even though he is sympathetic.

Maybe upon change of a part of the team or department under his or her authority

Agree on experts answers. Thanks for your invitation.