The way Kahane felt regarding any non Jew in Israel was that they had to go...and if not go, have no democratic rights to a Jewish state as long as they were peaceful.
The thing is, most of the non Jews in Israel are Arabs who claim Israel belongs to them and very few would even stay, even with all their rights except voting rights. What normal non Jew who lives in Israel would sing the Hatikva proudly at the point of "nefesh yehudia homia"?
It's not logical.