That covers a lot of things.
I do serve on juries, but not in the past week so I wasn't involved, never saw your post. I had a post removed once, and while I forget what the charge was, I recall thoughtfully raging about guns and gun control, and suggesting some extreme actions. Some of what I wrote might have been kooky, ridiculous, or even violent, and a jury decided it was. I understood why when I reread my post, they didn't need to explain in detail, even though I felt I'd toned down my rant.
Several people on this thread have suggested possible reasons, having seen your post before it was removed. Post 11 recalled it was about the current situation in the middle East, and you saying something in the "kooky" category about people who support Israel. Don't focus on the word "kooky" because it might have been perceived as bigoted or extremist. The US policy supports Israel, and most Jews support Israel, so saying anything negative about those who support Israel might be seen as that, anti American or anti Israel. You may feel what you wrote was reasonable, but a jury decided it was not appropriate for DU. There is no appeal process.
We all agree we can bash republicans on this site. As for other groups and topics, we need to be careful and understand there is diversity here. I've seen a number of posts that note the friction and divisions lately, regarding support for either side, but more for those who say both sides are to blame. This is a very divisive topic, and I think we all need to be extra sensitive to it. I've copied the rule in question, and again, it covers a lot of ground. I hope you can learn from this and move forward!
Do not promote ridiculous, bigoted, or extreme-fringe conspiracy theories. Do not promote extreme fringe views. Do not reference hate sites or other extremist/fringe sources.
Why we have this rule: Democrats are supposed to be part of the "reality-based community." Some amount of skepticism toward powerful institutions is healthy and appropriate, but that doesn't mean every paranoid fantasy is true. Posts about mass shootings being "false flag" operations, 9/11 being a controlled demolition, no airplane at the Pentagon, chemtrails, black helicopters, the Illuminati, or other nonsense make us all look like fools. This website may have the word "underground" in our name, but we are not extreme fringe.