All three remaining candidates have vowed to enforce the existing laws:

Three of the leading GOP 2012 Presidential candidates have made statements committing to enforce existing federal obscenity laws if they are elected, while the current administration still refuses to enforce federal obscenity laws prohibiting distribution of hardcore pornography, according to Morality in Media.

Morality In Media launched efforts in October 2011 to contact the 2012 presidential candidates, including President Obama, to obtain their respective views on the enforcement of obscenity laws. Thousands of individuals sent emails, made calls and even spoke to the candidates in person urging them to respond to the survey. As a result of these efforts, the following candidates responded.

https://twitter.com/#!/abcpatriot/status/180448383872401408

https://twitter.com/#!/michaelleung/status/180306333453651968

https://twitter.com/#!/vice_report/status/180465450138861568

Topsy produces 10 Santorum-related references (tweets, blog links, articles, other social media) for “pornography laws” over the past 21 hours. It produces the same number of pages of Romney-related references for “pornography laws” over 67 days.

A lot of conservatives will criticize Santorum for saying anything about pornography, but as he’s mentioned before, he responds to questions that he’s asked. What if he were to say, “No comment”? Do you think that might possibly be used against him?