It is an American tradition. It was tolerated years ago to help "even the playing field" with the power and wealth of Republicans.
Today it is a tactic of the New Left Stalinists.
In both cases it's dog-bites-man stuff.
Just cause it's rampant doesn't make it right. Oh, that's right.. the left gets to choose what "right" means.
For me, even if everyone and their brother do it, it doesn't make it right!!!