It’s pretty easy to get such a result when the war is unresolved and the MSM is heavily biased.
Plus, I suppose the poll never asked what the hell a practical alternative would be, or, “Is it acceptable for Iran to gain nuclear weapons?”
It's even easier to get such a result (and I'm surprised the number isn't 90% opposed to this stupid war) when President Trump himself has been putting out dozens of public statements and social media messages for months claiming that Iran's military has been decimated, their navy is at the bottom of the Persian Gulf, etc.