In April 2017, when debate on the tax bill that was signed in December of that year began, an economist wrote about the 43-year history of the Laffer Curve (It was first presented to Donald Rumsfeld in 1974). It has never lived up to its hype!
From 2012 to 2017, Governor Brownback of Kansas tried mightily to institute the Laffer Curve in Kansas. It was an utter and absolute failure.
In March of this year, Republicans tried to go back to the way taxes were under Brownback. The new Democratic Governor Laura Kelly held fast and refused to return to the failed past.
In December 2018, the tax cut was clearly a failure at doing anything but making the wealthy wealthier.
So it's difficult to know why Laffer is being awarded a Medal of Freedom by the President unless this is a "gaslighting" sort of thing.