Are Social Encyclicals Binding on Catholics?

If you had asked me as a young Baptist boy to explain the difference between Protestants and Catholics, I would have said that Catholics were the Christians who “have to do what the Pope tells them to do.” Now I’m an old Baptist and realize how naive I was. (I’m more likely to agree with the Pope than some American Catholics I know.)

I’m still unclear, though, on where Catholics draw the line of demarcation between complete freedom of conscience and deference to magisterial authority. After all, if a Catholic can support abortion and still receive communion, what is off-limits?

One area that I had assumed was clearly in the optional category was papal social teaching. But at Evangelical Catholicism, M.J. Andrew argues that’s the latest encyclical is binding on all Catholics :

The error that both Leo XIII and Pius X are correcting is one that is still made today in Catholic circles, namely, that the social teaching of the Church is in someway optional, non-binding, and/or merely prudential. Indeed, in many respects our inclinations and political proclivities, which often are merely products of our locale and social environment, are met by a powerful counterweight in Catholic social teaching. And rightly so. If, as the two aforementioned popes assert, our social life (i.e., family, political, and economic activity) are primarily religious and moral in nature, then the Church, by virtue of her authority in matters of faith and morals, is our touchstone for learning how to conduct that social life . . . .

Yet, we still encounter the stubbornly persistent opinion among Catholics that the Church’s social doctrine is not binding–and if it is authoritative, then it is not as important or consequential as doctrines of faith. But this position is certainly not to be found in Catholic teaching. Indeed, it is simply a pernicious prejudice.

Andrew proffers an intriguing argument (persuasive enough to convince this Protestant). But is he right? If so, why do so many Catholics ignore—much less dismiss—this encyclical?