The European nobles and politicians arrived in the gardens of Palazzo Brancaccio in gowns and tuxedos, ready for aperitivi with the Catholic power brokers and pilgrims from America.

Spritzes by the grand fountain progressed to entrees inside the palace, beef cheek cooked at a low temperature and served on orange potato velouté.

Brian Burch, President Trump’s nominee to be ambassador to the Holy See, dined at a head table next to Princess Gloria von Thurn und Taxis, the German aristocrat who befriended Justice Samuel A. Alito Jr., and alongside current and former members of hard-right European political parties. One of them, Antonio Giordano, a member of the Italian Parliament in Prime Minister Giorgia Meloni’s party, welcomed the several hundred guests to Rome, and discussed their shared “urgency of protecting the family.”

“Only together we can effectively conquer the demographic winter,” he said, nodding to low birthrates and a push for pronatalist policies.

After dessert, the guests followed the sound of live music up a marble staircase into salons lined with tapestries and lit with chandeliers. Eyes popped at the vast hall of mirrors, designed in tribute to Versailles. A gilded ballroom had walls stretching up 45 feet.

Brian Burch, President Trump’s nominee to be ambassador to the Holy See.Credit…Jacquelyn Martin/Associated Press