For both abortion and pornography, I firmly believe that we have to change a decent majority of citizens’ hearts before we should institute an outright ban. If the Supreme Court banned all abortion across the USA tomorrow on account of the unborn’s fundamental due process right to life, it might work to save more babies, but it could equally be likely to result in the loss of the rule of law., with very few babies saved. I’m torn, as a practical decision. If there were a general public consensus against abortion, the naysayers would have no choice but to accept. A more practical ruling, although quite possibly illogical, is to return the issue to the states (the Supremes could say that abortion of the unborn ‘person’ is illegal, but let each state decide if and when an unborn becomes a ‘person’).
With regards to pornography, an outright totalitarian ban could very well prove ineffective and again might read to the crumbling of the rule of law. Notwithstanding that concern, the government should clean up porn in limited ways, at the very least. More restrictions on the clubs, and way more decency on the public and semi-public airwaves (basic cable packages) would be great for starters, leaving the internet to private filtering.
You would not want to threaten usage of porn in any way (except child porn), as the government costs associated even with fines would likely be staggering. Attack the producers, at the club and airways level (public), letting the rest go until the hearts of men and women are more in compliance.