Various names are being mentioned in Rome as potential U.S. ambassadors to the Holy See under a new Trump administration, but whoever accepts the role will have to tread carefully amid some clear and expected differences. He or she will also have opportunities to cooperate on significant areas of convergence.

President-elect Trump’s positions on immigration, his hardline — or some would say realist — approach to Islam, and his ardent belief in capitalism are just some of the issues that could lead to a potential clash with this pontificate. Both he and the Pope have already come to blows on immigration when, without naming him, Francis suggested last year Trump wasn’t a Christian for wanting to build a wall on the Mexican border (Trump called the comment “disgraceful” but later moderated his remarks).

And yet his pledge to defend pro-life values, his clear sympathy for the Church (he reportedly continues to listen to a Catholic coalition group he set up during the presidential campaign) and his promise to defend religious liberty against “anti-Catholic bias” could bring significant levels of cooperation between the U.S. embassy and the Vatican. Trump himself once expressed admiration for Francis, albeit in typical jocular fashion, tweeting at the time of the 2013 conclave: “The new Pope is a humble man, very much like me, which probably explains why I like him so much!”.

A mix of potential candidates is being discussed in Rome, and the transition team is alleged to have already approached Trump’s rival for the Republican nomination, Ben Carson, to fill the role. A Seventh Day Adventist, Carson apparently declined the position and has since been appointed Secretary of Housing and Urban Development. Trump’s transition team didn’t respond when asked if it could confirm the story. Had Carson accepted, the former surgeon would have become the first non-Catholic to represent the U.S. government as ambassador to the Holy See since formal ties were established in 1984.

Other leading candidates are said to include Kansas Governor Sam Brownback, a former presidential candidate and senator, who converted to the Catholic Church in 2002. The 60 year-old father of five has been a member of Trump’s Catholic coalition of advisors, although he was not initially a strong supporter of President-elect, saying last August he had been “a Rubio guy” because he thought Marco Rubio had the best chance of beating Hillary Clinton before he dropped out of the race last March.

Another possible leading contender is former Speaker of the House, Newt Gingrich. A former Lutheran who then became a Southern Baptist, Gingrich was received into the Church in 2009. He ran for President in 2012 and was one of Trump’s staunchest supporters during last year’s presidential campaign, reportedly on the shortlist to be Trump’s running mate.

Married to Callista Gingrich (née Bisek), a Catholic of Polish-Swiss ancestry, they have hosted a number of documentaries as part of Gingrich Productions, including the film Nine Days That Changed the World — a tribute to the role played by Pope St. John Paul II in the fall of Communism in Europe and the rise of the Solidarity movement. Callista sings in the choir of the Basilica of the National Shrine of the Immaculate Conception and last October she and her fellow choristers performed in Rome, at the Church of Santa Maria Sopra Minerva.

But despite his strong Catholic connections, Gingrich is said to prefer being an informal adviser to Trump and so able to speak freely, something he’d be unlikely to do as ambassador. He has, in any case, said he’d most like to be a strategic planner for the Republican party with the aim of building on their victories ahead of the 2018 mid-term elections.

Other possible candidates include:

* William Simon, a pro-life Catholic businessman, philanthropist and a Knight of Malta who ran for election as Governor of California in 2002;

* John Klink, a former long-serving diplomat for the Holy See at United Nations and erstwhile president of the International Catholic Migration Commission. Klink, a papal knight, is also a member of both the Order of Malta and the Knights of Columbus; 

* Carl Anderson: Supreme Knight of the Knights of Columbus since 2000, Anderson is a former assistant to President Ronald Reagan and has been closely connected with the Pontifical John Paul II Institute for Studies on Marriage and the Family. He also has strong links with the Holy See, including serving on the board of the IOR (Vatican Bank), although the strength of such ties may pose a possible conflict of interest. 

But like a good number of Trump’s appointments so far, the President-elect's choice of ambassador is just as likely to be a total surprise. What’s more predictable is that the appointment will be made relatively soon, possibly just a few weeks after taking office, as his transition team has unusually issued a blanket mandate requiring President Obama’s politically appointed ambassadors leave their posts by Inauguration Day on Jan. 20.

Obama’s outgoing ambassador to the Holy See, Kenneth Hackett, had just retired from serving as head of Catholic Relief Services when the President appointed him in 2013. He told CNA Jan. 11 that he and his wife will leaving on Inauguration Day. "This will be my second retirement, so I will try to enjoy it,” he said.

The Obama presidency was not an easy time for U.S. diplomats to the Holy See, especially given the President’s policies on life issues and religious liberty, but Hackett was a popular ambassador who, while very aware of the significant differences, reputedly strove to work effectively on those issues which both the Holy See and the administration could cooperate on fruitfully.

He also deftly managed a smooth relocation of the embassy to within the compound of the U.S. embassy to Italy primarily for security reasons. Such a move is never welcomed by the Vatican, which is concerned that it signifies a downgrading of relations, and so always likes to keep embassies to the Holy See and Italy separate. 

Despite the inevitable areas of difference, Hackett told CNA he felt sure that on “human rights issues, on war and peace, and issues that affect people’s dignity” both the Vatican and the U.S. will continue to work together.