Because, simply put it's NOT true. Spin it as you wish. Both sides play the game, BUT there is way way more hate coming from the right than the left. This "both sides do it equally" is bull this election cycle.
TIS
"Mankind must put an end to war before war puts an end to mankind. War will exist until that distant day when the conscientious objector enjoys the same reputation and prestige that the warrior does today." JFK