Doesn't this imply that when our legislators pass laws from which they exempt themselves that they have broken the compact? Should we feel obligated to comply with such laws?
On face. But, I think the quote needs to be placed in the context of Rousseau and his thought (such as the "general will"); also, this assumes that our government is based on Rousseau's ideas. I think that should be answered before discussing whether or not compacts are "broken." Was it? Does the Constitution adhere to Rousseau's principles of government?
In the context of Rousseau's idea of the "general will" (and if i'm wrong, please correct me), I would almost think that passing a law which the legislators are exempt from would destroy the compact, yes, or at least make it irrelevant; but that's because the "legislators" (or the "general will") are the people themselves, more so than those understood by the Constitution (representatives of us, rather than us enacting our "will").
Should we feel obligated to comply with such laws?
I think it depends: if taken on face with your first comment, I don't think you should necessarily feel obliged. But, even then, I think it depends on the ends sought by the legislature with that law, like a good that is desired; it may depend on the premise(s) on which the government is based. Couple either one with the law, then decide whether or not to oblige it. There still may be reason to oblige the law, even if the legislators don't have to.
Under your scenario, what do you think about obligation to the law?