Lieberman's liberal policies are no worse than that of certain (non-Jewish) RINOs that almost everyone here praises. At least he understands (unlike many or most Dem politicians) that the world is a dangerous place.
It would be fun to watch the left's anti-Semitism come out in full force if Lieberman were selected. My how the leftists would sputter: "But, but, but, he is a J... Je... Jew... no uh, Zi... Zio... Zion... no uh, pro-Israel -- that's it! He's too pro-Israel!"
Not just the left. The paleo-right, too. ;)
Lieberman's problem is that his grasp of security issues is strong in the foreign sphere, but weak domestically.