It's interesting for me that you think this forum is biased toward anti-Israel and antisemitic, that sounds to me maybe I was wrong and misjudged the moderators, and it is very possible after one of the users explained why my first question was treated such and such, in that case it was really my fault, at least to a great extent.
However, as @ItalianPhilosophers4Monica stated in his answer, "yes, this site has a pro-West, pro-US, and yes, somewhat pro-Israel penchant", so if your posts are deleted there you should seek the problem elsewhere. Let review your question here:
My posts are routinely downvoted for not being inline with the
official anti-Israeli and anti-Semitic stance of this forum. I've been
routinely bashed, and on occasion even sanctioned by the moderators,
for not supporting the "community" demands to continue defaming Israel
and spread antisemitic misinformation, and for calling out those who
do.
here you have several points to say:
complaining about downvotes has nothing to say about moderations or even the general attitude of the community, as not every or perhaps even the majority of the community read all the posts, or react to them by upvote/downvote. I'm new here but not new to SE.
the reason for downvotes should be explained by the downvoters, some do give their reasons and many don't, but you are instead intention reading and judging the people who downvote (maybe hard to avoid it to be honest, I mistakenly do it occasionally as well) -- its arguably the downvoters' fault as well, since they declare a reaction but let people understand it the way they want, their UVs/DVs are not very useful indeed and maybe their absent is better than their presence?
sanctions by moderators I have nothing to say about, but I doubt if they have given you their reasoning to be "not supporting the community demands to continue defaming Israel and spread antisemitic misinformation, and for calling out those who do", maybe this is your translation of their explanation. You assume zero possibility for things to be somewhat different, being misunderstood by you. None of us here are infallible of any kind, so the possibility for us to misunderstand the others is probable, especially when we are extremely tired, angry, sad, or even happy. We should bear with each other, and I myself am no exception to this matter.
Now, not only are my posts being downvoted, they're being actively
removed.
I have talked with several people of very different ideologies and beliefs, with no serious problem. What can make a serious problem is perhaps labeling, especially when the person being labeled rejects the attribute given to him/her but we again insist on it. Once I left SE some years ago for being engaged with a person, an Indian PhD student, who continuously insisted on Shia Muslims being Mushrik. To some extent avoiding labeling is so difficult, when believing in something is so deeply rooted in the person's belief structure. For example here users are frequently label Hamas fighters as terrorists, ignoring the news saying many civilian Israelis killed were indeed killed by the Israelis forces themselves, even seemingly on purpose. This is a labeling as well, if I as well have used such labelings in calling the pro-Israelis somewhat pro-criminals/genociders. People themselves should decide with respect to what audience saying something will be understood as annoying/wrong labeling. For example, in Israel you can easily assume Hamas/Iran forces terrorist and no one blame you for misusing the label, and the reverse is true in Iran when Israeli/CENTCOM forces are called terrorist.
But here people are diverse, so maybe more caution should be taken so that a useful contribution and beneficial idea-sharing happens. I personally have learned a lot here, so to me it is worth to bear all such annoying labeling and still remain here, at least until now, but you can choose if that's OK with you either as well.
On other SE stacks, the "delete" button is usually reserved to spam
posts, abusive posts, or posts that should have been comments. My
answer is neither of these things.
Why was it deleted, other than the inherent inability of certain
anti-Israeli users to accept the fact that Israelis may not be as bad
as they want them portrayed??
I agree with you that questions/answers should be tolerated more in such issues. Maybe those who care about such issues can themselves probably improve/rephrase the question, for the main point to remain immune. For example I ask "why are you enemy to what I believe and all the believers like me, defending the enemies of humanity?", and they improve it by saying "why you disagree with the point I just said?" ... this might help both sides having said their points in a more calm atmosphere ...
my 5 (soapboxy) cents ...