You have to go far back into history to find a pope and a U.S. president who are so much in agreement. But when they meet in Washington, differences may make themselves more apparent.

This Wednesday, the pope will mingle with the people of Washington and the celebration will be reminiscent of 2008, when candidate Obama hoped to heal the world. In those days, Obama was the cool, idealistic outsider looking to infuse an old office with new magic. All that goes for Pope Francis as well, well-liked in the U.S.; in fact, [he's] more liked than the institution he leads. Beyond these personal similarities, however, President Obama and Pope Francis have political priorities that are in such agreement that conservatives complain that Francis is “Obama's pope.”

But that designation is off the mark because it implies the president is able to control the pope's thoughts. The exact opposite is in fact the case: Francis doesn't see the United States as the focal point of the world. To be sure, he is indeed an American pope but he is, decidedly, a South American pope. He has been shaped by Argentina — that is to say, by poverty — and by government failure. But he is also shaped by a joy of life that is not dependent on material possessions.

US Is Foreign to Him

He comes as a first-time visitor, so the United States is foreign to him. The pope is a different kind of American, [one] who is accustomed to the poverty of South America and who has a good deal of criticism for the land of capitalism, the waste and the overcrowded prisons. The pope comes as a foreigner to this nation, and therein lies the attraction. He will find loving words for his hosts – but at times uncomfortable ones as well.

Nonetheless, a rare affinity has developed recently between pope and president, notably regarding the subjects of environmental protection, social equality and American-Cuban relations. The military goals of the world's most powerful man seldom coincide with those of a man who has only “soft power,” the power of words and gestures, available to him. The latest example of that hasn't been seen since the 1980s, when Ronald Reagan and Pope John Paul II opposed communism.

Seldom Have a Pope and a President Agreed More Closely

Through 2008 and 2009, Obama was himself a sort of secular pope; he wanted to be the president of peace and was rewarded with the Nobel Prize in return. But opposition to this style of politics, [stressing] diplomacy and gentle persuasion toward Iran, is considerable in Washington. In the struggle for public support, it is extremely helpful for Obama to have the backing of the pope.

Francis, on the other hand, comes from a part of the world that often correctly sees the U.S. as part of the problem. The pope obviously sees Obama as part of the solution as well. He realizes that his words on environmental protection are bolstered when the president agrees with him, especially now as a climate summit in Paris looms, as does a presidential election that will decide the direction of future U.S. foreign policy.

A Powerful Critic of Republican Policy

Republicans have unknowingly brought a powerful critic of their policies into their house. When they invited the pope to address Congress, neither his encyclical on the climate nor his part in secret negotiations between Cuba and the U.S. were public knowledge. Now Pope Francis will be able to see how far from the mainstream the Republicans really are with their denial of climate change.

They claim the abundance of raw materials is a gift from God. The pope should remind them that the price of wasting them will be paid by someone else – mainly the poor – and that governments must do more to ensure a more equitable distribution of the benefits, including in the United States. It will then become clear that a candidate like Bernie Sanders, who according to U.S. standards qualifies as a socialist, is saying many things that are taken for granted as acceptable and even desirable in other parts of the world.

Francis Doesn't Fit the Mold

But this pope doesn't fit into Washington's rigid right-left pattern and therefore the Democrats will have to get used to occasional warnings. Francis also doesn't fit the description of “Obama's pope,” because he is more conservative than Obama on issues dealing with family and society. Many consider the pope liberal because of his refusal to condemn homosexuals. In Washington, however, he may also stand for traditional marriage between one man and one woman and support the rights of the unborn, something that would be welcomed by Republicans who seem to have rediscovered an old campaign issue.

Obama has had to learn over the years that soft power and persuasion solely by diplomacy have clearly defined limits. Francis, on the other hand, may come to realize just how limited his power is in America. Washington politicians will shoot selfies with him and tell him things they think he'll agree with. Pope Francis is in Washington for just a few days, during which he'll do what foreigners do best – he'll hold a mirror up to his hosts.