He is an outspoken critic of Israel, but more importantly, he has been recognized as an antisemite since he was in high school. For Jadue, there is no distinction.
The Simon Wiesenthal Center wrote about Jadue last year:
He charges Jews control of the media and dual loyalty: “It is an insult that the State of Israel through its agents here in Chile wants to import the strife” ... “they have to learn and define if they are Chilean citizens.”Last year, Recoleta’s Municipal Council passed a resolution stating, “Palestinian people have been the victim of a deliberate plan of violence and terror by armed Zionist groups ...”Jadue insists, “... The leaders of the Jewish community in Chile act on behalf of the State of Israel in Chile …,” adding, “I get along very well with the Jews, with the Zionist I have certain problems.”Jadue is always referring to Chile’s Jews as the “Zionist” community of Chile.At a time of soaring global anti-Semitism and Islamist terrorism striking from France to the Philippines, Jadue insults three Abrahamic Faiths: “If you are born into a Jewish family, you can legitimately believe that you are part of the Chosen People and you can kill the Palestinians to stay with their lands’ possession…
Recently, Jadue's 1983 high school yearbook entry surfaced. His fellow students joked about his well-known hatred of Jews in his biography.
The bio says that "this antisemite was seen in all coastal waters," that he will become the leader of the PLO "to cleanse the city of Jews," that "he sings manifestos against his beloved and esteemed neighbors 'the Jews'" and that a proper gift for him would be "a Jew he can aim at."
(It is also notable that his high school classmates felt that Jew-hatred was a joke.)
His antisemitism pre-dates his current claim of being merely "anti-Zionist."
Understandably, the Jewish community in Chile is very concerned about an antisemite becoming president.