One graph with no context or information about how to interpret it was posted. Anyone can cherry pick. You can cherry pick Kansas and whatever that graph was supposed to mean, and I can point out that the most liberal state in the country, California, has the highest average cost of living in the country causing it to be seen as a rich man's state.
I mean, you can cherry pick anything. Economics isn't an exact science, we're not talking about global warming or evolution/natural selection, where 99% of the worlds economists agree on what the best economic systems are. In the end, we're talking about opinions, and both sides will fit the empirical data to their own political views and find ways to justify it. There is not a broad consensus. And even if you can definitively tie what happened in Kansas to a piece of policy, things change based on geography, demographics, and many other factors which make it not so black and white.
I mean, I admit that you can't show me any data that would convince me one way or the other, because I don't believe economic theory si developed enough to answer the question. If it were, 99% of the economists in the world would have reached a consensus, just as scientists have with global warming, vaccines, and other pressing issues.
There's 1 study from the IMF about the effects of trickle down economics. Great, now where's the other 999 studies necessary to form a reasonable level of confidence that their study was correct?
Maybe in 100 years.