Can someone be both a supporter of Jews and against Israels existance?
Yes. Israel is a Zionist state that was founded by atheist Zionist Jews. Zionism is a new movement that was established in 1882, while Judaism is thousands of years old. There are many Jews that are against Zionism. Norman Finkelstein, an American Jewish historian, has likened the Zionists to the Nazis and authored several books exposing Zionism: http://www.normanfinkelstein.com/deutsch… Ilan Pappe, an Israeli historian, authored a book about the Israeli ethnic cleansing of the Palestinians: http://en.wikipedia.org/wiki/The_Ethnic_… There are Jewish organizations and groups that are dedicated to exposing Zionism and its links to anti-semitism and Zionist collaboration with the Nazis: http://www.jewsagainstzionism.