Based on Zionist principles, the law was intended to ensure that the State of Israel would be a Jewish state and a home for the Jewish people.
The law was later amended twice. The first time was on August 23, 1954, under then-prime minister Moshe Sharett, when a provision was added to deny citizenship to certain people, such as those with a criminal record.
The second change was more significant and on March 10, 1970 under then-prime minister Golda Meir, the law expanded the Right of Return to those who were not deemed Jewish according to Orthodox halacha definition, but also to those who were married to a Jew, converts to Judaism, or the grandchild of someone who was Jewish. Those not eligible for citizenship, however, were those who converted to another religion despite still being Jewish according to Halacha and, following a 1989 High Court of Justice ruling, Messianic Jews, as long as they don't have Jewish ancestry.
The reason for expanding the definition of being Jewish remains in dispute such as the "Who is a Jew?" argument that Israeli politicians and rabbinical authorities have debated continually throughout history. One notable point of dispute over the expansion was that it referred to similar criteria used by the Nazis during the Holocaust. They, of course, did not follow Halacha when determining if somebody was Jewish.
