The immigration debate -- dominated this summer by White House hopeful Donald Trump's controversial comments -- could take on a more serious tone if Pope Francis decides to tackle the issue during his September visit to the United States.

Chances are good that the leader of the world's more than 1 billion Catholics will weigh in on the issue. Lawmakers and immigration activists hope Francis' message might resonate beyond Capitol Hill and inspire members of Congress and their constituents, Roll Call reported.

In the past, the pontiff has not shied from commenting on matters pertaining to the U.S. immigration system, the publication recalled. Last year, for instance, he referred to the the surge of Central American children crossing the border into the United States a "humanitarian emergency."

"He's been clear on our failure to respond appropriately to immigrants and refugees," Rep. Jim McGovern told Congressional Quarterly. "I don't think anyone will have any doubt on where the church stands on immigration after the pope visits the United States."

Maria Sotomayor, an outreach coordinator for the Pennsylvania Immigration and Citizenship Coalition, told the Catholic News Service that it was highly likely Francis would again tackle the issue at some point during his trip, which includes a visit to the White House, an address to a joint session of Congress and an appearance at the World Meeting of Families, a major gathering of Catholic leaders in Philadelphia.

"Through his vision, Pope Francis will show our Congress that the whole world is watching what our leaders here are doing and that their lack of action on immigration reform will not go unnoticed," Sotomayor predicted.

Throughout his pontificate, the Catholic leader "has displayed a deep interest in international affairs," CNN noted. Among other issues, he has weighed in on the civil war in Syria, hosted a prayer service between Israeli and Palestinian leaders at the Vatican, and ruffled feathers with Turkey when he called the 1915 killing of 1.5 million Armenians a "genocide."

The Argentine-born pontiff, the first from the Americas, is also credited with playing an important role in the rapprochement between the U.S. and Cuba.