Ah yes, that old tired canard. Total BS.
So what do you think caused it? Capitalism?
The historical evidence that Smoot-Hawley had a LOT to do with it is extremely strong.
The left always argued it was a canard, while conservative economists argued it wasn't. We have now reach the point in the U.S. where Marxism reins unchallenged.
Obviously Smoot Hawley did nothing to end the Great Depression.
The so-called Smoot-Hawley Tariff Bill did not cause the Great Depression, but for sure, it exacerbated the effects, and most notably, it was NOT repealed by the FDR New Deal regime that assumed power in the US in March 1933, mostly on the promise to “end Prohibition”. FDR did get authority to regulate the tariff rates independent of action by Congress, but he did not, ever, abolish the tariffs altogether.
And FDR had the power.