The answer to your question lies within the relationships between Israel and the West.
Some thinkers in their books such as “Zionist Christianity and fundamentalist America” (Persian translation: مسیحیت، صهیونیست و بنیادگرای آمریکا ) and “Jewish Messiah” have tried to elaborate the goals and programs of Christian Jewish union, in particular in west, especially United States of America, and highlighted its religious and strategic aspects and claim that the old "America’s strategic support for Israel” and “the influence of Jewish lobby in decision-making and supporting of the Jews in the west” analyzes are not convincing and that the eternal support of Israel has more links than military, political, security or economics and in fact the relationships between Jewish Zionists and evangelical Christianity has origins in their religions and culture and their belief in the future of the world is based on the theology of nuclear Armageddon and the final war in the Middle East.
There is another trend in America’s power structure contest that is called “extreme-right Neoconservatism” . the new generation of Neoconservatisms have emerged with the beginning of Reagan’s presidency and culminated in the presidency of George bush (son). this trend has legacies like the collapse of Soviet Union, declaration of “New century America” and design and execution of the invasion of Iraq. This group calls America the greatest power in the world and thinks America’s culture is the most original one. They also try to make America dominate the world and like Jewish Zionists, support Israel regime and to protect it they proposed the “Great Middle East project” in which Israel is the center of it.
The third great power of America are Jewish Zionists that are gathered together as the name of Jewish American residents. powerful lobbies like AIPAC that are defenders of profits and interests of Zionist regime in layers of decision-making system of America, are manifest evidences of their will and power over America. The strategic goal of Jewish Zionism with the aid of their incredible deep roots in America’s society, is the never-ending support of America for them and supporting the programs they have in the world. Ever since Israel was invented, those reasons made America support Israel In terms of military and economy, made them support that regime in International societies and disavow any statement made against Israel regime in the United Nations and veto them in the United nations security council and force America’s allies to also support Israel regime and accept their demands.
Active presence and the money of Zionists in the America’s election
One of the things Zionists rely on is their high influence on America’s different elections. Two things make Jewish Zionists to have determinative role on America’s election, especially America's presidential election. First thing is the 90% participation of them in the election and the second is money. Jews are very active in elections, they collect financial help from people and let America use their media tools. Newspapers like New York times, Washington post, wall street journal and television channels like CBS, NBC, ABC and even CNN are all under influence of Zionists and in election all of these medias are directed towards the favorite candidate of Israel.
That is why presidential candidates race against each other to gather Israel’s support. In 1976, Carter with the help of “Edward sanders”, chief of AIPAC, became the president of America but after 4 years and with the support of the same lobby of him, he failed. The cause of that is an approval of an anti-Israeli statement that “Donald McHenry”, the America’s ambassador in the United Nations, on behalf of Carter supported it. But Reagan used exactly the same thing to get Israel’s support and hey became America’s president for the second time in 1984, because he removed Jew’s taxes and he brought Israel into NATO. Also Clinton more than Bush (father), was serving Israel, in a way that in 1996 he succeeded to get 78% of their votes.