I question the identification of Southern Populists as "socialists". Some urban "Progressives" might have been, but socialism has always moved hand-in-hand with Central European statism, through the importation of Forty-Eighters (socialist Germans) and socialist German Jews (the same ones Hitler exterminated right after the Anschluss), all of whom were statists in some degree or other.
A populist believes in the People, a statist in the supremacy of the State. Jeffersonian rural populists were anti-statist and, because bankers were pigs-at-the-trough statists and access-capitalists (Hamiltonians in other words, whose beau ideal was "Empire without the King"), the populists opposed them both before and after the ravages of the gold standard led them to embrace Free Silver and William Jennings Bryan.
My grandfather worshipped Bryan; he also was a "lunch-bucket Democrat" and Al Smith man (because Smith was Irish Catholic, like him), and not an urban socialist/prog/Communist. He spat on such people, despised the people around FDR and especially Eleanor. He said, significantly, that he voted for Franklin Roosevelt once.
No, Jeffersonian populists were not statist socialists, German-style. They didn't like empires, and they didn't like banks that liked empires. Neither did Jefferson or Jackson.
Jefferson and Jackson were not statists; William Jennings Bryan and his followers were.
You do realize I'm an avowed Hamiltonian? Alexander Hamilton and the Federalists were the prototypical American conservatives, unlike the Jacobin sympathizers who opposed them.