ability to cleanse oneself

＝自浄能力

辞書比較

物書堂 ウィズダム英和・和英辞典（三省堂）

物書堂 ジーニアス英和・和英辞典（大修館書店）

物書堂 オーレックス英和・和英辞典（旺文社）

 

Unfortunately, political parties have never had the ability to cleanse themselves, and it's not something we can expect in the future either.