Why Does U.S. Continue to Back Israel/AIPAC?

Seriously, why? I ask myself this every time there is news of the Israeli government "committing atrocities like they got immunity" (yes I just dropped Jay-Z in the first sentence of a political post, hereby eliminating any credibility one may have given me), against the Palestinians. When the region, and the world for that matter, turns to U.S. it continually shows a pro-Israeli bias and refuses to even examine the other side of the coin. I grew up with a Jewish mother, I respect what Israel means to the Jewish population of the world, but at some point enough is enough. Here is my basic opinion on the Israeli/Palestinian conflict: First of all, when Bush insisted on fair democratic elections in Palestine and the Hamas leadership group won, President Bush tried to deny the legitimacy of their authority. As much as I agree that Hamas is generally an evil, bigoted, organization, they won the election. Second, I have to say, I can see where Palestinian "terrorists" come from. Ask yourself this question, if your mother or your girlfriend or your brother or cousin or uncle was killed in a "war-strike" from Israel, how would you feel about the Israeli government? Just because they call it an act of war, why is that better than firing a missile at Israel? How is that, being a terrorist organization, but when Israel thrashes thousands of Palestinians, it is warfare? Terrorism is a type of warfare. And, it's the only way that angry Palestinians can seek revenge for the bloodshed caused by Israel. It then becomes a vicious circle where Israel fires back, and pounds Hamas with missiles, causing more resentment in the region. The question though, is why do U.S. politicians allow AIPAC to influence them in such a way that no matter the situation, the United States backs Israel? I wish I had the answer. Despite, most of the world pressuring Israel to lay off Hamas, the U.S is currently doing their typical blind pro-Israel song and dance. If you're expecting a change in the way business is done from the U.S. point of view when Obama enters office, think again, Obama has been a staunch Israel-supporter from day one and has surrounded himself with even more pro-Israel advisers (i.e. soon-to-be Chief of Staff Rahm Emmanuel). I'm sure people more knowledgeable about this will want to puke after reading my elementary analysis, but it is what it is. There's a comment section, enlighten me...