Its leadership now insists that not only has the party purged its ranks of anti-Semites but that it now shares a common cause with Israel and the Jewish people: controlling the spread of Islam. Indeed, the Freedom Party is pledging to protect ethnic “Judeo-Christian” culture on the continent by stopping Muslim immigration and imposing more surveillance on Austrian mosques. That mission, they argue, has become all the more urgent given the recent arrival into Europe of nearly 1 million refugees from the Middle East.

“Islam is not a part of Austria,” Hofer said at the anti-Semitism conference, while seated near the famed Israeli Nazi hunter Rafael Eitan. “By the year 2050, 50 percent of the children [in Austria] under 12 will be Muslims. . . . The kind of politics that is permitting a changing face of Austria and Europe has to be opposed.”

His campaign to court Jews and Israelis has gone all the way to the Temple Mount, where Hofer made a pilgrimage during a 2014 visit to Jerusalem. In April this year, Strache, the Freedom Party’s chief, laid a wreath at Jerusalem’s Yad Vashem Holocaust memorial in a move rife with symbolism.

The Israeli government — still cautious about the Freedom Party’s far-right roots — did not officially greet its delegates. But David Lasar, a top Hofer adviser who is also Jewish, said that private meetings took place in April between Strache and some Israeli government ministers. He declined to name names.