Why do republicans take it so far?

I'll admit, when Bush was president, Democrats called him things like dumb or they'd laugh and mock him and do interpretations but Republicans, why do you guys go so far with President Obama. I hear things like he needs be killed, lynched, burned, he's a traitor, people constantly degrading his wife. President Obama has gotten more death threats in his first 2 years than the last 4 presidents combined. Arent yall taking it a little too far? And I know all republicans are not doing this but it just seems the vast amount. I mean I am 100% honest to God, on my life, I would not want to be a democrat politician right now ....i'd be scared for myself and my family.