The questions is what can't we do? To Representative Pete Stark? Nothing.
I don't think the Health Care Bill violates the 13th amendment, but congress does overstep its bounds by requiring people to purchase a service that they may not want to.
Now, if congress meddles further and commands that doctors must perform certain services to certain people and accept a legislated wage, that could be construed as a form of servitude (even if we think the remuneration is adequate). It is no different or less reprehensible than the draft.
Stark isn't alone in his obnoxious conception of government (and of his own powers), but at least he's honest about it. Most Republican legislators talk about limiting or reducing government in fora such as this, and then do whatever they want in Washington.