Novak simply misses the point regarding bishops and the abortion issue. What the bishops are being criticized for is not their stand, which they are entitled to, but their behavior. Indeed, he carefully avoids mentioning issues like the denial of communion to parishioners and the threatening of Catholic voters with divine retribution if they don't vote the Vatican party line. How does Novak fit such behavior into his model of "serious moral argument" conducted in a "rational and civil manner?"
In the interest of civility, Novak might take a step away from his own style of hyperbolic and specious argument. The Vatican and "rock videos, movies and magazines" (whichever ones he means) are not the only available moral choices--tens of millions of non-Christian Americans reject both and yet live moral lives. And if any comparison is to be drawn with slavery, it is that of women as a class, on the basis of religious ideology, being denied the right of reproductive choice.
Should Novak have his way, it will be the pro-choice side, not the Catholic Church, running the underground railroads.