US president friend of Israel: asset or liability

Since President Obama was a candidate worries began to arise regarding his stance towards Israel, would he be a ´good´ or a ´bad´ President for Israel.
We, Jews in the Diaspora, and I assume many in the US, tend to view US elections in this frame, a President of the United States, for us, is the one who is good for Israel, American concerns aside.
Bush was considered a true friend, Obama raised questions, and concern.This led me wonder what is the meaning of ´good´, what is the difference between being good or being ´correct´, of doing the right thing, that would certainly imply political considerations, since there seems to be no ´true´ friendship without ulterior political motivations that would benefit the states involved. It is also true that the Jewish lobby is perceived as ´strong´´, and they might be so, but in reality how much would they be able to achieve if the matter was not in the interest of the US as well.
President Bush, as mentioned before, regarded as a great friend of Israel, did not, until the very end of his presidency, got involved in searching for a solution to the Israeli-Palestinian conflict; so I guess being a friend means letting the other believe he can do whatever he pleases, believing that in the end it will not have to deal with international’ opinion, or with the reality on the ground.
Obama has not said anything others have not previously stated, that is, the necessity to stop settlement activity and the two state solutions; in my view, despite concerns of his ‘Islamic’ background, nothing new has been stated that could be viewed as being against Israel by Obama or his administration.
In my view, the idea of a US president who is a friend of Israel has been a liability in many cases instead of being an asset. What I am suggesting is that defending Israel’s right to exist, Israel’s sovereignty and its right to be recognized among the nations of the world should not regarded as a ‘favor’ by a friend. It is and should be presented as the just, correct and proper thing to do by any country that abides by international Law. By presenting the US position regarding Israel as ‘objective’, the US is demonstrating that is it doing what is right for any state to do regarding other whose survival is at stake, and maybe then it would be perceived as a reliable negotiator and fair player by the nations of the world, especially the Arab nations of the world, hopefully dropping the ‘excuse’ of friendship that implies profit for one of the parties, as a reason for impending successful negotiations.