袍笏登场páo hù dēng chǎng

袍，古代官服；笏，古代大臣上朝所执手板。袍笏登场，就是扮演大臣的演员登台演戏，现在常用来比喻坏人上台，有贬义；或比喻新官上任，有讽刺意。

例袍笏登场也等闲。——清·赵翼《瓯北诗钞》

英taking position of power,as in a dress rehearsal; dress up and go on stage—said of a puppet upon his take-over;