What message will Pope Francis bring to America?

BUENOS AIRES, Argentina (WPVI) -- It will be fascinating to see what messages Pope Francis brings to America.

You may be surprised by this, but the pope's popularity ratings (yes, even popes have poll numbers) are substantially down. His approval rating was 59 percent last month, which sounds pretty good until you compare to 76 percent in July of last year.

One of the likely reasons for the plunge is the pope's broadside against capitalism.

In a speech this past July in Bolivia, Francis called unbridled capitalism the dung of the devil, responsible for much of the world's poverty.

He has also issued an encyclical on climate change, calling on rich nations, like the United States, to end policies that are "destroying the planet."

More than half the Congress, where the pope will speak on his first American stop, takes issue with both pronouncements, as do many Americans. But as we've been told in his homeland of Argentina, the key to what they call "Francismania" is not necessarily what he says, but how he says it.

He is no dour pope. His smile can light up a crowd of millions, and his informality, humility, humor, and ability to connect have made him a rock star.

But according to Sebastian Lacunza, editor in chief of the Buenos Aires Herald, this public persona is no accident.

Lacunza explains, "He used to be a very serious person. He looked really worried. Now his smile is clear and friendly, He's warm with people. So his personality, his behavior as a human being also changed a lot. I'm sure that he knows because he reads the press and he's very interested in public opinion. And all his messages and gestures, all that he does, is regarding public reaction and the media reaction."

We have talked to many people during our week in Buenos Aires, and regardless of their perspective, they share extraordinary respect for Jorge Bergoglio, the man who would become Pope Francis, and his love of the poor, his humility, his lack of pretense, and the way he has changed the conversation from Vatican leaks, bank scandals and sex abuse to notions of mercy, inclusiveness, and making the church more welcoming.

They say even if there are no specific changes in church doctrine, Francis will have changed the church.

What will the pope say in Philadelphia? One must remember he is here for the World Meeting of Families, so issues about the family should be at the center of his message.

One might suspect he will apologize for the sexual abuse of children by priests. But when he's gone, and one of the most anticipated events ever in Philadelphia is over, many may remember that smile, and his charisma more than the specifics of his message.

That's how a lot of folks remember him in his hometown of Buenos Aires.