Now that Joseph Biden has officially tossed his hat into the ring for the Democratic nomination as President of the United States, he’s quickly become his party’s presumptive front-runner despite the fact that he’s tried twice before without notable success.

Although the nineteen months between now and November 2020 represent several lifetimes in American politics, meaning anything could happen - and then unhappen, happen again, and metamorphosize into something else entirely by the time all is said and done - should Biden actually succeed in unseating Donald Trump, he would bring to the job a wealth of experience in engaging the world’s preeminent “soft power,” i.e., the Vatican and Pope Francis.

Biden and his wife are both Roman Catholics and regularly attend Mass at St. Joseph’s on the Brandywine in Greenville, Delaware. He wears a rosary on his left wrist, a gift his younger son, Hunter, gave to his older son, the late Beau Biden, after a visit to the shrine of Our Lady of Guadalupe.

Biden’s experience of the Vatican while holding political office dates to at least June 2011, when he traveled to Rome for an unannounced private visit to then-Pope Benedict XVI. President Barack Obama had met Benedict in 2009.

As the Vice President from 2009-2017 under Obama, Biden was the highest-ranking Roman Catholic in America at the time. He was in Rome to mark the 150th anniversary of Italian unification.

Details of Biden’s encounter with Benedict, which was not included on the list of the pope’s regular scheduled events that day, were never provided. However, it is believed part of the discussion focused on the U.S. role in the Middle East since both Biden and Benedict had met with other political officials the same day to discuss the issue.

Two years later, Biden returned to the Vatican for the inauguration of Pope Francis’ papacy in March 2019, leading a delegation that included House minority leader Nancy Pelosi and Republican Governor Susana Martinez of New Mexico.

Biden made a subsequent visit in 2016 for a Vatican conference on regenerative medicine, offering a keynote speech at the event advocating for a cure to cancer following the death in 2015 of his eldest son, Beau, who had brain cancer. At one point, Biden also gave an address at the Vatican’s Casina Pio IV, the headquarters of the Pontifical Academy of Sciences.

He praised Pope Francis for his comfort, his humility and his social agenda, voicing hope that everyone would have the opportunity to meet the Argentine pope.

However, though Biden is no stranger to the Vatican, his history with Catholic leaders in the U.S. hasn’t always been rosy.

Shortly after announcing his decision to run for Vice President in 2008, Biden came under fire from U.S. bishops for his position on issues such as gay marriage and abortion, saying that while he personally believed that life begins at conception, he would not force his views on other people and would therefore run as a pro-choice candidate.

Archbishop Timothy Dolan in 2008 chastised Biden and then-House Speaker Nancy Pelosi, saying at one point, “It bothers me if any politician, Catholic or not, is for abortion.”

“In my mind, we’re talking about a civil right, we’re not talking about a matter of Catholic Church discipline. We can’t allow the noble pro-life cause to be reduced to a denominational issue,” Dolan said, adding that “Church tradition is equally clear that bishops are the authentic teachers of the faith.”

“When prominent Catholics publicly misrepresent timeless Church doctrine - as Biden and Pelosi regrettably did (to say nothing of erring in biology!) - a bishop has the duty to clarify,” he said.

Several bishops at the time insisted that despite his personal views, given his pro-choice political stance if Biden presented himself for communion in their diocese he would be refused.

Bishop Michael Sheridan, who oversees the diocese of Colorado Springs, said at the time that Biden should know [he would be turned away] and, “I would do everything I could do to make sure that he knows he ought not to be receiving Communion.”

Leaders in the U.S. church were also critical of the “Obamacare” proposal, which included contraception, including some abortifacients, as part of standard women’s healthcare.

Prelates who joined the choir of opposition were Bishop Fred Henry of Alberta, Ottawa; Archbishop Terrence Prendergast of Paterson, New Jersey; Bishop Arthur J. Serratelli of Birmingham; Bishop Robert J. Baker of Atlanta; Archbishop John F. Donoghue of Charlotte; Bishop Peter J. Jugis of St. Louis; Archbishop Charles Chaput of Denver; Bishop John Ricard of Tallahassee-Pensacola; Joseph Martino of Scranton, Penn., and then-Archbishop Raymond Burke, who had just been named Prefect of the Supreme Tribunal of the Apostolic Signatura, the highest judicial authority of the Catholic Church apart from the Pope.

Biden has also given the Vatican grief over an inquiry into the quality of women’s religious communities in the United States, specifically the Leadership Conference of Women Religious (LCWR), an umbrella group with some 1,500 members. The group claims to represent 80 percent of American sisters since its members are leaders of their respective religious communities.

Following his visit with Benedict XVI in 2011, the New York Times reported that Biden had told the pope to “lighten up,” because the Vatican was being “entirely too hard on the American nuns.”

In 2012, Biden has expressed a willingness to join the LCWR on their first “Nuns on the Bus” tour, during which they were outspoken on issues such as abortion and same sex marriage, advocating in favor of Obamacare despite the U.S. bishops’ resistance. 2012 was also the year that the Vatican launched their inquiry into the LCWR.

The New York Times reported that during a brief handshake with Pope Francis following his inauguration in 2013, Biden praised the sisters for their activism on issues such as poverty and healthcare.

If the past is prologue, therefore, should Biden be elected, he likely would again face a complicated relationship with his own Church.