Former Pennsylvania senator Rick Santorum at the South Carolina Tea Party Coalition Convention in Myrtle Beach, S.C. (Randall Hill/AP)

Catholics are supposed to listen to the pope. Why? As explained in their church’s catechism: “For the Roman Pontiff, by reason of his office as Vicar of Christ, and as pastor of the entire Church has fullsupreme, and universal power over the whole Church, a power which he can always exercise unhindered.”

That’s a pretty broad mandate.

But when Pope Francis starts cautioning Catholics against breeding “like rabbits,” some Catholics don’t like what they hear — including once and future Republican presidential contender Rick Santorum.

“The pope is the leader of the Catholic Church, and when he speaks as the leader of the Catholic Church, I’ll certainly pay attention,” Santorum said on “The Hugh Hewitt Show.” “But when he speaks in interviews, he’s giving his own opinions, which I certainly will listen to, but from my perspective, that doesn’t reflect the idea that people shouldn’t be fruitful and multiply.”

Santorum wondered whether Francis’s fear of excessive multiplication was aimed at the world’s poor.

Maybe he’s speaking to people in the Third World, but the problem certainly in most of the Catholic world is not procreation,” Santorum said. “I mean, in Europe in particular, you have birth rates that are only over, just a little over one for every two people. So this isn’t a global problem, and I don’t know what the pope was referring to.”

Host Hewitt wondered whether “the left” would say Francis “is about to lead the Church in a different direction on contraception.” Santorum said no way. 

No, well look, the bottom line is that’s not going to happen,” Santorum said. “I don’t think anyone who seriously looks at this believes that it’s not possible to happen. I mean, the pope is the pope, but the pope has a lot of other people around him who advise him. And you know, the most important thing is that as a Catholic, I believe he has the Holy Spirit, and the Holy Spirit isn’t going to let him make that kind of mistake.”

But: “Well, I mean, it’s sometimes very difficult to listen to the pope,” he said.

With the interview, Santorum added his voice to those of other Catholic conservatives angered by Francis’s comments about income inequality and gender. One, sidelined Cardinal Raymond Leo Burke, took to criticizing the “feminization” of the church earlier this month.

“Apart from the priest, the sanctuary has become full of women,” Burke said. “The activities in the parish and even the liturgy have been influenced by women and become so feminine in many places that men do not want to get involved. Men are often reluctant to become active in the Church. The feminized environment and the lack of the Church’s effort to engage men has led many men to simply opt out.”

Santorum is the father of seven — and one of the parents Francis may have sought to appease when he appeared to walk-back his comment by praising large Catholic families.

“Healthy families are essential to society,” Francis said. “It provides us with consolation and hope to see so many large families who welcome children as a gift from God. They know that every child is a blessing.”

En route to the Philippines, Pope Francis condemned last week's deadly attacks in Paris, but said it's wrong to insult religious beliefs. (Reuters)