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A poll in February 2014 revealed that the leader of the Catholic Church was seen favorably by 76% of Americans and unfavorably by 9%.
Mostly responsible for the drop? People who self-identify as conservatives. Only 45% of conservatives view him favorably this year, compared to 72% last year. Meanwhile, among Protestants and other Christians, only 52% of them see him in a favorable light, compared to 73% last time they were polled.
Over the past year, the pope has spoken vehemently about the need to curb climate change and called on governments and citizens to do their part to stop it, a stance with which many Republican politicians - including Catholic presidential candidates - disagree.
He has stressed the importance to fight inequality in a meeting with President Barack Obama and spoke out against "the big world economies that sacrifice man at the feet of the idol of money."
Many conservatives' beliefs are seemingly at odds with many of the battles the pope has chosen to fight. Yet some of those battles - like fighting for the less fortunate and against the idolatry of money - are relatively basic tenets of Christianity.
Catholics have also become slightly more negative about the pontiff - only 71% of them now view him favorably, compared with 89% back in 2014.
His overall favorability in the US is almost back down to the same level as when he was first elected in March 2013 - but the percentage of people seeing him unfavorably is 6% higher now than in 2013. A higher percentage of Americans also now say they have never heard of him or don't have an opinion.
Two years into his papacy, Francis viewed more favorably than Pope Benedict XVI was at the same point (52%) - but less favorably than John Paul II was in 2005 (78%).
Overall, the head of the 1.2 billion adherent strong Catholic Church is still seen favorably in the US, and enthusiasm to see him on his first visit to the US in September this year is peaking. The Philadelphia transit ticket system had to be shut down after too many people bought rail passes for the pontiff's upcoming visit.