1.   But his behavior clearly undermined his authority.

2.   Dictators and schoolteachers have tried to control it, fearing its contagious power to undermine authority.

3.   Knowledge of their relationship would undermine their authority, or so they thought.

4.   The president faces issues that can catch him off guard and undermine his authority.

5.   This must have infuriated my father and undermined his authority.

6.   The conversations were designed to undermine her authority so she felt that she could no longer work for the company.

7.   She tried to undermine my authority by complaining about me to my boss.