a.) "Trickle-down" again? C'mon people. Will the same people be ok if we switch to labels such as "anti-science" or "pro-abortion" on Roe v. Wade?
b.) Comparing Clinton's job growth with Reagan's? Puh-leez. 1.) Clinton had the generally-healthy economy that Reagan bequeathed him and a slight recession at the end of the Bush years from which to recover. Reagan/Volcker had the high inflation of Johnson-Nixon-Carter monetary policy to deal with (leading to the recession in 1982-- a time that was worse than the Great Recession).
2.) Clinton benefited from Reagan winning the Cold War, allowing him to divert military/defense resources to more productive uses.
c.) But to argue in favor of the author's thesis: One would not expect the necessarily-small decreases in marginal tax rates to be all that consequential-- or helpful to tax revenues or to the economy. When JFK (the original "supply-sider") cut the top rate from 91 to 70%-- and when Reagan teamed with a Democratic House to cut the top rate to 28% (and index taxes for inflation-- a huge, vastly-under-rated policy change)-- the gains were (expected to be) much larger.