During the 2012 race for the White House, three of the top candidates for the Republican presidential nomination – Mitt Romney, Newt Gingrich and Rick Santorum – pledged to strictly enforce laws that arguably ban Internet pornography and make its consumers eligible for prosecution.

The assurances brought scrutiny to the candidates and the group that solicited them, Morality in Media, which was led by former Justice Department official Patrick Trueman, a proud participant in federal pornography prosecutions during the Reagan and Bush administrations.

Trueman's group is now called the National Center on Sexual Exploitation, and he’s finding 2016 presidential candidates less eager to respond to a survey that includes questions about porn’s legal status alongside ones about prostitution, sex trafficking and child exploitation.

Of a GOP field that included more than a dozen candidates when the group released its survey in early November, just one – Santorum, a former Pennsylvania senator who withdrew from the race Wednesday after performing poorly in the Iowa caucuses – has responded.

Santorum last year told U.S. News he could not remember his previous anti-porn pledge, which included a statement on his website condemning the “scourge of pornography” and promising to end it with legal action. But he reclaimed his original position this year, according to the NCOSE.

Ohio Gov. John Kasich’s campaign refused to answer the survey and the rest of the candidates – including front-runner Donald Trump, who once appeared on the cover of Playboy magazine – have not responded, leading the group to ask supporters to blast the campaigns to demand answers.

One of the survey's 10 questions declares "[f]ederal obscenity laws prohibit distribution of hardcore pornography on the Internet" and on TV, and asks candidates if they would "direct the U.S. Department of Justice to vigorously enforce federal obscenity laws."

"It is shocking that no front-running candidates from either party have made it a priority to address issues like sex trafficking, sexual violence and the public health crisis of pornography,” Trueman says. “America deserves a president that will be a leader in combating all forms of sexual exploitation.”

A state legislator in Utah recently introduced legislation that would declare porn consumption a public health crisis, lifting the spirits of anti-porn campaigners, though the cold shoulder from presidential campaigns clearly stings.

In 2012, pornographers largely laughed off Santorum's statements, but legal scholars said there could in fact be a resumption of prosecutions against Internet porn companies and even individuals who watch pornography at home.

The Supreme Court ruled in 1969 in Stanley v. Georgia that private possession of sexually obscene content is constitutionally protected, but has not shielded private receipt of pornography.

Federal obscenity laws formerly used to prosecute porn cases are still on the books, but prosecution of ordinary viewers and major companies dropped off during Bill Clinton’s presidency and were not a priority for the George W. Bush administration, much to anti-porn campaigners’ dismay.

The trick to winning a porn prosecution is to prove that certain content violates community standards for obscenity, meaning juries in different parts of the country could return different results. That could be good news for a person who sells pornography in New York City, but bad news for any U.S.-based company whose website is accessible in Arkansas.

Legal scholars previously pointed out that foreign porn websites are beyond the reach of U.S. law, but the latest survey takes that into account, and asks if candidates would support adopting a U.K.-style proposal to “block pornography to user accounts unless users specifically opt in to receive pornography.” (Santorum answered yes to that question and all others, the group says.)

Other questions ask candidates to ensure the Department of Health and Human Services undertakes “a major effort to abate the effects of pornography addiction” and insist that the Federal Communications Commission actively police “sexually explicit or sexually suggestive content.”

Though it increasingly appears there will not be a return of federal prosecutions for porn featuring consenting adults, some unforeseen shift in public opinion or national leadership could change that.

“You can’t prosecute them all … but you can find certain types of pornography that are sufficiently unpopular” for convictions, UCLA law professor Eugene Volokh said in 2012. But, George Washington University law professor Jonathan Turley pointed out then that “what Santorum would consider obscene is obviously far greater than many Americans.”

Still, Trueman says a future administration could lead a successful crackdown, noting the Justice Department in 2012 won a guilty verdict in Los Angeles against a fetish porn producer who made videos of sex acts featuring bodily waste. That case began during the Bush administration.