This graph confuses me, as did the More Unions, Lower Job Growth. Shouldn't one of these data legends go along the horizontal, and one along the vertical?

Or am I just dumb?

This is just one way to show data. You don't "have" to do anything when displaying data, but these make the point, I think, because you can see the trend lines (drawn by Excel) essentially doing opposite things. I wish I had more programming skills and could make the graphs more interactive. Then you could go in and see which states are outliers, etc. You could also go in and see where the two lines intersect and try to take your state policy to the correct side of that line. That's why I've linked to the data, though, so people can do that themselves.

The left axis and blue dots show state and local tax burden rising.

The right axis shows lower job creation for those states with higher taxes.

Not all graphs are x,y.