And, support it they do, per a long string of comments by unhinged SWP entry-ist Cort Greene on this blog post.
Support it they do, per Wiki's page on the SWP, which notes that from Greens on left, they're basically the only party that supports it. Even their Trot cousins at the Socialist Equality Party, while being Xi Jinping tankies and other nuttery, reject Zionism.
WHY, I don't know. This IS a turning. In the 1970s, the SWP was strongly anti-Zionist. That said, per its SEP foes, by the 1980s, it might have been anti-Zionist, or not, but it was also antisemitic. Jack Barnes, called out by the SEP back then, is STILL head of the SWP, and per his linked Wiki page, has led all of the various expulsions within the SWP within the last 50 years. AND, per Louis Proyect, as of 2017, at least, it was BOTH Zionist AND antisemitic. And also, per Proyect and this piece, Jack Barnes has no more than 1,000 or so acolytes including Cort Greene. Also per that piece, the SWP has been, per Cort Greene calling me a fascist, quasi-fascist supporters of US imperialism for at least 20 years.
Think Stalin's various twists and turns over 25 years, double the length and shrink it down to a political group 1/100, nay, 1,1000, if that, as big as the CPSU. It's no wonder the remaining true believers are paranoiacs, even by the standards of left factionalism.
It might be tempting to tie it back to Zionism's roots, namely its roots in Palestine, not Europe, and especially in Poland, but it's not that. It's Jack Barnes.
That said, the rest of that "strongly antisemitic"? The SEP, a bunch of actually doctrinaire actual Trots, is truly nutters itself.
Marxists insist that the temporary strengthening of Zionism is the historical outcome of the catastrophic defeats of the European labor movement that led to the annihilation of six million Jews by the fascists. Without the combined betrayals of Stalinism and Social Democracy which prepared these defeats, the Zionists could never have attained the influence they acquired during the post-World War II period.
That ignores that much of Zionist migration to Mandatory Palestine happened before the Ribbentrop-Molotov pact. It often happened LONG before that. Ben-Gurion? 1906. Jabotinsky, the most racist and virulent of old Zionists? Pre-WWI.
To put it bluntly? Today's Socialist Workers Party is the LaRoucheites of alleged leftist groups.
That said, beyond Zionism being a particular virulent and particular virulent form of nationalism, today's Israel is nowhere near socialist. Zibbutzes are more hasbara than reality. And, the Labor Party? A nothingburger, and as much influenced by the "Third Way" in the last thirty years as many other such parties.