The Democrats dislike Israel because it is a standing example that the world is not safe, and if the world is not safe - then demilitarization and increased social spending would be irresponsible.
After 55 years of wondering why so many American Jews vote democratic, you may have answered my long standing question.
Support Israel and there is less social project money available here.
Rush made a similar comment about the State of Israel today (how socialistic they are). The difference is that they also know the value of defending themselves.
While that may be part of it, in my view the most fundamental reasons are twofold:
1. Israel is wealthy and prosperous and stable, and the Arab Muslim states that surround them are not. For leftists, this is a terrible crime as it "proves" that Israel is oppressing the Muslims. Remember, for liberals it's all about economics and class. Culture, religion and outlook have nothing to do with it.
2. Israel's best (and maybe only) ally is the United States. This makes them doubly guilty in the eyes of the left, because the United States is the single biggest problem in the world today, so our friends are automatically suspect.
On a side note, some of the worst, most blatantly biased reporting I have ever seen from CNN has come during this war. Hexbollah couldn't buy a better commercial. Perhaps the above points are driving this.