But From the River to the Sea started out as a phrase used by the PLO with a meaning closer to what people are accusing it of being these days (although not entirely accurate), that gradually branched out and became used by people of all stripes who support Palestine, including support for a binational state. I don't think the slogan is particularly useful especially given how divisive it is, and it distracts from the real issues at hand, but it's not going away and painting everyone or even a majority of people who use it as genocidal/antisemitic/wanting ethnic cleansing is a troubling and demonstrably false take that's meant to delegitimize opposition to Israel's invasion/bombing of Gaza and U.S. support for it, and Israel/Israeli policy in general.
I'm not saying everyone who uses this slogan is an antisemite, obviously, but can we acknowledge that there's maybe a bit of a problem when so many people within this movement are so willing to adopt a slogan with antisemitic roots and connotations? Like, is is really that hard to say "we don't f**k with that sh*t" and find a different chant? But no, many of these people (whom I am sure don't think of themselves as antisemites) seem to revel in the transgressiveness of it all. I think that does speak to a serious problem within the "pro-Palestinian" crowd that does in the long run contribute to the spread of antisemitic beliefs and tropes.