That is what the business class says isn't. But if that were true wouldn't the opposite be true, i.e. supply side tax cuts lead to economic growth and more jobs but that's not what has happened.
You need only to look at the Trump tax cuts and the state of Kansas tax cuts of 2012...oh don't remember that one, well everyone should. Kansas was a real life experiment in supply side economics and well...to say if failed horribly is an understatement.
"Kansas’ 4.2 percent private-sector job growth from December 2012 (the month before the tax cuts took effect) to May 2017 (the month before they were repealed) was lower than all of its neighbors except Oklahoma and less than half of the 9.4 percent job growth in the United States.
Likewise, the number of Kansas residents reporting income on their federal tax returns from a partnership or “S corporation” (two of the main types of businesses that the tax cuts exempted from income tax) grew by 4.1 percent between 2012 and 2015, well below the 5.4 percent growth for the United States and below all of Kansas’ neighbors except Missouri.
Moreover, Kansas revenues plunged, leading to cuts to education and other vital services and downgrades in the state’s bond rating. On June 6, 2017, the legislature terminated what Brownback had termed a “real live experiment” in supply-side tax policy, repealing the business profits exemption and moving income tax rates back toward where they had started."