Pope Francis' reference to Donald Trump as a "wall builder" who is "not a Christian" last February appeared to have no effect on the U.S. Republican presidential front-runner's popularity among Catholics, a new Reuters/Ipsos poll shows.

In fact, Trump's popularity since the time the Pope made his critical remarks has increased by more than 20 percent, Breitbart reports.

Fifty days before Pope Francis made those remarks on Feb. 18, Trump's popularity among Catholic Republicans averaged just 39.8 percent, the poll says. Fifty days after the Pope spoke, Trump's popularity among these Republicans has risen to an average of 47.9 percent, an increase of 20.4 percent.

The Pope spoke about Trump aboard a plane on his way to Rome from Mexico when a journalist asked him his impression of Trump who vowed to deport 11 million immigrants and build a wall along the U.S.-Mexican border, thereby splitting up families.

In response, Pope Francis said anyone who thinks only of building walls and never of building bridges is no Christian, since this way of thinking is foreign to the gospel.

"I would only say: if he said these things, this man is no Christian," Francis said. "But we'd have to see whether he said these things. And in this matter, I would give him the benefit of the doubt."

The next day, Vatican spokesman Father Federico Lombardi clarified that Pope Francis' remarks were not meant as a "personal attack" on Trump, but merely reflected the Pope's conviction that bridges are preferable to walls.

Lombardi also said that the Pope was not trying to tell Catholics how to vote at the upcoming U.S. election.

Regardless of what the Pope said, many U.S. Catholics have indicated that they would still be voting for Trump in the November election.

Breitbart notes that although Pope Francis enjoys a 90 percent favourability rating among his Catholics in the U.S., the Pope has no special authority in political matters as far as these Catholics are concerned.

The question now is: Why are Catholics supporting Trump?

Writing for Catholic Online, David Drudge offers an explanation: "Catholics have one thing in common: They don't like being told what to do. This may seem ironic for members of a Church that is also one of the planet's last absolute monarchies. And while Catholics will often listen to the Pope, sometimes begrudgingly, they will absolutely rail against fellow Catholics, including clergy, who tell them who they cannot vote for."

Drudge notes that Catholics make key voting blocs in swing states, such as Ohio. "How Catholics go, so too does the nation. It was Catholics who elected Obama, twice," he said.

Although Catholics are split on the raging issues of abortion and immigration, "they're tired of establishment politics that they feel has sold them out," Drudge says.

"Many have been working for a decade without seeing a significant rise in pay. They see perpetual war which is making them weary. They are tired of Obama and his policies which the Republicans seem unwilling to actually fight. They're tired of Republican ineptitude," he says.

These Catholics are also tired of listening to their own religious leaders whose sermons on morality appear to have no effect on the nation's life, he says.

Hence, "Catholics are choosing Trump because he seems to be their best choice for genuine, conservative change," Drudge says.