The porn industry has an X-rated reaction to Rick Santorum’s vow to crack down on pornography if he’s elected president: Butt out.

Two giants in the industry contacted by msnbc.com scoff at the Republican presidential candidate's claims that porn is causing “a pandemic of harm” in America and contributing to violence against women.

Nonsense, says Hustler publisher Larry Flynt. Absolutely no proof, says Steven Hirsch, founder and co-chairman of Los Angeles-based Vivid Entertainment, one of the largest makers of erotic movies.

Flynt notes that a 1969 commission set up by President Lyndon Johnson spent millions of dollars studying the impact of porn and concluded there was no evidence such materials were harmful.

“You have guys like Santorum come along and they bring out the bogeyman every chance they get,” Flynt said. "You will be hard-pressed to find anyone that can point out to you a study that shows harm is caused to anyone exposed to porn materials."

“I find it ironic that Republicans (like Santorum) are out there wanting less government and government intruding into our lives, but when it comes to moral issues they want government to legislate morality," says Hirsch. "It doesn’t work. It will never work.”

Santorum, a former Pennsylvania senator who is trying to woo social conservatives, says on his presidential campaign website that if elected he will hire an attorney general who will “vigorously” enforce federal obscenity laws curtailing distribution of hardcore por