Just Asking

What is the difference between the Boston Marathon Bombers and the people President Obama and academia adore, Bill Ayers and  Bernadine Dorhn?
How about the thugs who killed a researcher in Madison, WI. in 1970.  The thugs included Karleton and Dwight Armstrong, David Fine and Leo Burt.  The left idolized these thugs and murderers.
So, please me tell the difference between all these bombers and murderers.