Pope Francis' Popularity Declines in the US
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Pope Francis' popularity among Americans may be waning, according to a new Gallup poll.

The pontiff's favorability rating in the United States has dropped from 76 percent in early 2014 to 59 percent this month, Gallup reported this week. This 17 percentage-point decline puts his approval rating close to the 58-percent rating he received in April 2013, soon after he became pope.

For the most part, Catholics and political conservatives — two groups that remain most devout to the modern papacy — drove the rating down. Among these groups, 71 percent of Catholics think of Pope Francis favorably, compared to 89 percent last year. Moreover, 72 percent of conservatives approved of the pope last year, whereas only 45 percent approve of him now. [Papal Primer: History's 10 Most Intriguing Popes]

Although the new survey results suggest many Americans are shifting their favor away from the pope, a rising number reported not knowing him well enough to rate him. In fact, one-quarter of Americans today say they have never heard of the pope or have no opinion of him, compared to 16 percent in 2014. This lack of opinion contributes to the overall decline in favorability, according to Gallup representatives.

Too progressive, too quickly?

Pope Francis, who serves as the religious leader for 1.2 billion Catholic people around the world, has focused his papacy on issues that involve protecting the poor, strengthening interfaith religions, respecting gay and lesbian members of the church, and making environmental conservation a priority.

The pope's decline in favorability among conservatives may result from his denouncement of "the idolatry of money" and his support for the science behind human-caused climate change — two beliefs that often conflict with conservative political views.  

However, the pope may not be progressive enough for liberals, a group that also reported a drop in favorability by 14 percentage points — from 82 percent in 2014 to 68 percent now. Liberals have taken issue with the pope for not allowing the ordination of women as priests and for continuing to prohibit priests from marrying.

But Pope Francis' favorability among Americans may rise again soon, with his first planned visit to the United States in September. The pope will make stops in New York, Philadelphia and Washington, D.C., and will be the first pontiff to address a joint session of Congress.

Americans can be somewhat fickle in their admiration of the pope, history shows. When Pope John Paul II, who led the Roman Catholic Church from 1978 to 2005, visited the United States in 1993 and 1999, he was rewarded with a boost in popularity. Similarly, when Pope Benedict, who preceded Pope Francis as pontiff from 2005 to 2013, visited the U.S. in 2008, he reached his highest favorability rating among Americans.

The Gallup poll gathered data from telephone surveys conducted from July 8 through July 12, 2015. The poll included 1,009 adults ages 18 and older living in all 50 states and the District of Columbia.

Elizabeth Goldbaum is on Twitter. Follow Live Science @livescience, Facebook & Google+. Original article on Live Science