I don't think that Bill Mahr is by any means a clever pundit that should be taken seriously. He's a pompous ass most of the time. He thinks he is rational, when often, he's full of logical fallacies.
However, there is a glut of that sort of crap on TV, and the right has a near monopoly on it.
It is nice that Mahr is critical of eating meat, but that's one sunny spot on his BS train. For example, I'm an atheist just like him, but his movie was a rambling mess that framed atheism solely as a vindictive reaction of religiosity. Even his atheism seems badly reasoned, and from my perspective, that is nearly impossible... but he did it.
And to top it off, he's often sexist and unfunny and often exhibits classism. He's not much of an ally.
The video on him ranting on the Santorum supporter who had 19 children is on that same vein.
Mahr behaves like he is speaking truth to power when he is unsavory, but in reality he barely says anything radical; instead he is just unsavory and from the general vicinity of the left. meh. Pop Media.
"The worker has the right to leave his boss, but can she do it? And if she does quit him, is it in order to lead a free life; where she will have no master but herself? No, she leaves to sell herself to another employer. She's driven by the same hunger. Thus the worker's liberty is only a theoretical freedom, lacking any means of realization; an utter falsehood."