The majority of those hecklers are actual Obama volunteers who make a career from following republicans in order to cause chaos.
They are absolute hypocrites, using freedom of speech to fuel their own leftists ideals but limiting the right of freedom of speech to those they oppose.
You can't have it both ways. You can't have freedom for yourself and mute the opposition. Everyone in America has freedom of speech...even if according to Obama our founding fathers "didn't built that (freedom of speech)....someone else did". I am sure he would love to take away more freedom from the mouths of millions of Americans and only limit freedom of speech to himself and his own stuttering.