By Mark Abrams

PHILADELPHIA (CBS) — In the wake of a successful papal visit to Philadelphia, speculation is growing in some church circles about the potential for Archbishop Charles Chaput being elevated to the rank of cardinal.

Philadelphia has been without a cardinal for four years – since the 2011 retirement of Cardinal Justin Rigali – who now lives in Knoxville, Tennessee.

Veteran Vatican journalist Rocco Palmo, who follows the papacy and the Philadelphia church, says while Philadelphia has traditionally had a cardinal running the church, Pope Francis has demonstrated in selections of new cardinals that history doesn’t always play a role.

Rather, Palmo says, it’s recognizing growth in the church across the globe — and growth, he says, is not what’s happening in Philadelphia.

“Atlanta is about to have more Catholics than Philadelphia. Miami already has more Catholics than Philadelphia,” he says. “Orange County, California, which is its own diocese, has more Catholics than Philadelphia. This is no longer one of the ten largest dioceses in the United States.”

Palmo says it’s not impossible, but the chances are remote that Chaput will be elevated to red-hat status anytime soon, if ever.