Mud sticks
Definition 1 of 1
Pro Tip 1/3Emotional Impact
Understand that this phrase often carries negative feelings, suggesting unfair lingering doubts. 
She lost the court case, and though she's appealing, mud sticks.
Pro Tip 2/3Social Caution
Use cautiously in sensitive situations because it implies that someone's reputation has been unfairly tainted. 
He's working hard to clear his name, but mud sticks.
Pro Tip 3/3Colloquial Usage
Mud sticks is informal, best used in casual conversation or in the media, but not in formal writing. 
In the world of politics, mud sticks, even after the scandal fades.