What about ism

In the past I have pointed out how politicians get off the hook by using what I called the teenage defense, that is, Mom everyone is doing. It seems that no matter how badly a politician behaves as long as they can point out that someone in the other party did the same thing then it is OK. It is not necessarily OK but it dies as a news story when it can be shown that both sides do it. I see now that they have a new phrase that describes this behavior, "what about ism". Mine is better.