Yes, and I dont know why, either. I know that we like to believe that we are more moral and decent then the other side, just like the other side believes it of us. I may upset a lot of Conservatives, but the Left thinks that they are the MORAL ones.
The truth is that we are all universally more interested in our own ideas than the other guy's. It is literally a war of ideas. Playing fair in war, can lead to long periods of LOSING. Just like the Republicans in Congress through the 60's and 70's.
Republicans have only recently woken up and discovered that if you want to win, you have to get down in the mud and wrestle that pig.
Winning clean is not as important as WINNING period. Losers accomplish nothing.
And gain nothing.