knock (one) off (one's) pedestal
1. To cause one to lose a leading or prominent position. At the end of the day, I think voters just wanted to knock the prime minister off his pedestal.
2. To reduce or damage one's ego or pride; to humble or humiliate one. I'm really glad that pompous oaf lost his court case—maybe that will knock him off his pedestal. It's about time someone knocked Sarah off her pedestal. Her snotty, rich-kid arrogance is intolerable!
knock (one) off (one's) perch
To cause one to fall from a leading or prominent position. At the end of the day, I think voters just wanted to knock the prime minister off his perch.