I have two children, now grown up. When they were young, I was annoyed most days by their bickerings.......if I pull up one of them for an offence, the defense would not be about that particular offence, but an accusation that when the other sibling did something comparable, I said nothing so why am I doing so now................Usually, I would not have any recollection of this previous offence, which would put me on the backfoot.
I am sure most parents of young children have the same experience.
Politicians do the same.........talk to BJP about Gujarat riots, they say what about Congress and the anti Sikh riots. CM of UP says what about Mayawati ill-treating IAS officers? So if someone commits a crime, it's now open season on that particular crime.
My children's bickering comes to mind every time.