If you think we are at the left of the Laffer inflection point then you are really out to lunch.
Um... The discussion was about a flat tax. We have no idea what the equilibrium point for that might be, especially for a national tax. It’s much harder to move to a new country or work off the grid than it is to move to another state. Since the rate would have to be between 17% and 20% to fund the current rate of spending, the results would be interesting. It’s been quite some time since I took micro or macroeconomics. Do you suppose the point would be called the coefficient of elasticity?