Polls have never been faithful of actual public sentiment on any political subject since the end of times. People will not give their true opinions in polls on any subject that could be perceived as complex. Also it is actually very hard to have a good representation of the entire population of your country.
Just take the crosstabs of the survey you linked: about the 2024 election vote, in this survey, 70% of people polled are negative toward trump. The 2024 election results gave almost 50% of the popular vote to trump.
My point is only that this poll do not bring any valuable information here, just like any poll. The public sentiment toward Luigi Mangione seems favorable in appearance, but twitter is not representative of the US population either. So, who knows?