Meryl Yourish perceives an anti-Israel--and perhaps even anti-Semitic--strain in the positions and rhetoric of today's left in general, and the Democratic Party in particular. Israeli-American blogger "Haggai" disagrees, arguing that while some of the ferment on the left's radical fringe may be disturbing, the mainstream Democratic Party--as typefied by the largely pro-Israel frontrunners in the 2004 candidacy race--is still at least as supportive of Israel as the Republicans.
I agree with Haggai that anti-Semitism hasn't made serious inroads into mainstream American politics, in either party. I also agree with him that describing Bill Clinton as anti-Israel (as Yourish does) is extremely unfair. One may certainly object to his administration's policy on the Israeli-Palestinian conflict, and in hindsight one would have a pretty strong case. But it's hard to find daylight between his position at the time and that of Ehud Barak, who was, after all, voted into power by a solid majority of the Israeli electorate. A policy that is supported by most Israelis can't really be called anti-Israel.
On the other hand, the collapse of the peace process has unmistakably changed the political equation in the US with respect to Israel. Today, a pro-Israel position simply "fits" better in the Republican Party than among the Democrats. Affection for Europe and the UN, the Israeli Labor Party, Israel's peace camp, and negotiation over confrontation in general all tend to draw the Democratic Party away from the current Israeli government, while the opposite tendencies in the Republican Party tend to draw it more towards Sharon and his coalition. September 11th only intensified these trends, by adding into the mix the differing approaches of the Democrats and Republicans to Iraq, terrorism and the Arab world in general--again, with the Republicans finding more in common with Israel than the Democrats.
Now, I'm not claiming that this movement has any kind of deep moral significance. It's easy for those of us to whom Israel is important to forget that for the vast majority of the world's people, Israel is like any other country (and there are literally dozens) locked in a regional battle. Opinions on it thus tend to line up somewhat arbitrarily based on the kind of vague partisan correlations I've described. They can also flip fairly quickly; consider, for instance, the contrasts between the administrations of, say, Carter and Clinton, or Bush the father and Bush the son.
Precisely because these views are not terribly deeply-held or carefully-considered, they tend to be quite simple and polarized ("Israel is intransigent and belligerent", or "Israel is a valuable and steadfast ally"), and to determine opinions on particular sub-issues (peace plans, violent incidents) irrespective of the details of the sub-issues themselves. For a typical Democratic or Republican Party activist, the obscure fine points of the "road map" proposal, for example, will inevitably take a back seat to their party's overall perceptions of the reasonableness of the Israeli government. And today, those overall perceptions will be considerably more positive among Republicans than among Democrats.
For Americans who consider their domestic partisanship far more important than a minor, faraway conflict, there is no apparent harm in forming opinions on the latter in this somewhat capricious manner. Conversely, those who feel strongly about Israel should be prepared to be as nimble in their partisan affinities as major parties are in their Middle Eastern ones. Meryl and Haggai are, of course, free to decide which category they belong to.