When I saw this comic, all I could think of was, hey, there's a man intimidating a woman with a knife while dictating his political views to her--not allowing her to actually be a part of the discussion. She even expresses her apprehension of his knife pointing at her with uneasy humor. It is also not lost on me that the creator utilized a man of color to be the vehicle for this implication of violence, but that's a whole other can of worms I'm not going to bring up here.
I doubt Muir intended this, but it probably came out subconsciously. It seems to me to express that the idea of health care reform (and, for that matter, any liberal ideas) are the product of silly emotional girls who need a MAN to tell them what's what, and then make sure to dominate her and show her who's boss; perhaps the knife, along with symbolizing the desire to do violence to liberals, also symbolizes the desire to use one's masculinity to dominate them through sex (regardless of whether there is consent involved, of course--even if there is "consent" in this kind of sex, it's often someone either too intimidated to say no, or someone complicit in their own oppression, which can happen for a variety of reasons).