The debt, the economy, Obamacare, have all been talked about at great length and in great detail by Santorum, and will continue to be addressed 'front and center.'
The fact that the Obama administration is lawless is a major problem, and Santorum's bringing up that the laws against pornography (among many others) have been ignored, is a major concern......or at least should be......for all Americans.
Don't be afraid of the moral issues in a campaign. They are winners because the majority of Americans don't have a problem with addressing them.
You say that Santorum is not really making an issue of this, and that “most” Americans agree with him on this.
But in reality, the moral decay in this country, is the direct result of those same people who you claim agree with Santorum.
Morality begins in the home, at the family level, and is taught through example. The American family is no longer what it was 3 decades ago. What you see on the Internet these days, as well as what the younger generations are doing to promote this kind of thing, is a direct reflection that morality is no longer a priority or is being taught or enforced at the family level.
It is way too late to legislate it now and legislation has never worked anyway. (Remember Prohibition?)