I agree with your broader points. I think however that if American socialism came out of agrarian populism, it'd be even less likely to be "properly" socialist, because fundamentally, agrarian populists in the United States never had a problem with the principle of private ownership of land or being rich. Their problem was simply that they didn't own enough land privately, that they weren't rich.
The problem is that the rich people own all the good land. The problem is never that individuals per se are allowed to own their own land.
Certainly there's nothing problematic about I owning my own land.
Me owning my own land, why, we couldn't have proper liberty in this country unless I knew that I owned my land and nobody could take it away from me!
Well, part of my point is that "proper socialism" could look substantially different. Certainly the Farmers' Alliance would never have stood for collectivizing their own land - but the Omaha Platform already called for the public ownership of railroads, telegraphs, and telephones; the National Grange and plenty of other movements were big into co-operatives on everything except land ownership (e.g. crop marketing, grain elevators, farm supply, banking); we know from OTL's New Deal that most farmers were fine with the federal government setting prices and conducting central planning; even if it starts out as a purely "farmers' interests" type of thing I can see a situation where a Populist government adopts basically socialist measures and then backfills a justification behind it, one that leaves a space for private property ownership in the land (perhaps even "up to a certain limit" - after all, we like small family farms and don't like big agricultural corporations or private monopolies) but adopts recognizably socialist (though perhaps non-Marxist, or incompletely Marxist) principles not merely as opportunism but, after a few decades contesting power, as genuine belief.
Kind of off topic, but your example reminds me of a funny anecdote in the
Cambridge History of Russia:
Ted Hopf said:
...Shakhnazarov relates details of the meeting of the CC commission on Poland that took place in early 1981 under the chairmanship of Mikhail Suslov. The Soviet ambassador to Poland at the time, Boris Aristov, reported that the Polish peasantry, despite its traditional ideas, had turned out to be a far more reliable support for the regime than the working class, which had fallen under the influence of both Solidarity and the Catholic Church. This is heresy to the orthodox Soviet model of a working-class vanguard, and Ponomarev interrupted, saying that the Polish leadership needed to collectivize its private farms. Aristov demurred, repeating that Polish private farmers mostly supported the government. Ponomarev then reminisced about the 1920s and the great feat of collectivization. Suslov, 'a reservoir of quotations from Lenin', cited an appropriate one on collectivization. Suslov and Ponomarev then opined about Lenin and collectivization. Finally, Ustinov said, 'Mikhail Andreevich, Boris Nikolaevich, why are we talking about communes when with each passing day Solidarity is threatening to remove the party from power!?'
I'd be inclined to expect that in a Communist version of the United States, you'd still have Jim Crow in the South, you'd still have the same lack of tolerance for homosexuality and transgender expression as in OTL, etc. Exploring the movement for civil rights under these conditions would make for a very compelling and intriguing story.
I definitely agree - both in the case of a Communist party that starts out racist and continues that way and in the case of a Communist Party that starts out with the same high-minded anti-racist ideals as OTL* but sells its principles for power. (Or one that stakes out a position that's different from Jim Crow but still oppressive - for example, "Southern Black sharecroppers are an oppressed proletariat that needs to join hands with their white brothers and overthrow the plantation class - but organizing that on racial lines is a wrecker plot to incite hatred between the working class - and
Northern Black migration is a capitalist plot to drive down the price of labor and break strikes, so we need to introduce internal passports". Or an implementation of the OTL Communist platform plank of "self-determination for the Black Belt" that looks less like actual autonomy and more like, well, the actually existing ethnic SSRs.)
*Yes, I know, plenty of early Reds were incredibly racist, but you know what I mean
A lot of the American Socialist movement was ethnic politics. Often German or Jewish or (if anarchist flavored) Italian. And a lot of the German Socialists ended up as Sewer Socialist (ergo, practical good government types). There was also the Scandinavian ethnic factor (Minnesota Farmer-Labor, and North Dakota's Nonpartisan League).
A lot of the lefty progressivism was a kind of class politics in which old family WASPs supported very progressive reforms partly out of a distaste for the new money industrial class.
Western agrarian populism was very focused on particular sorts of bread and butter issues. They wanted better credit terms, public services, stability in the agricultural price markets, better prices for grain elevators, railroads, and warehousing, etc.
This is true, but I do want to explicitly point out that I don't think it's any less true of the Democrats or Republicans of the time.
(Now I'm thinking about - and this is not more than TLIAD-level fuzzily plausible - the idea of "movement socialism" taking over a previously less ideological party in the manner of OTL "movement conservatism". Say the Red Scare doesn't happen somehow but the alt-Great Depression still does - but the government that gets credit for the recovery is a conservative, relatively laissez-faire, Republican government. As the Old Deal Era curdles into dogmatism, ideological sclerosis, and economic malaise, a new band of ideological renegades backed by a new set of activist groups - labor unions that had stagnant membership for decades but are suddenly growing at a rapid clip, public intellectuals like John Kenneth Galbraith and Michael Harrington, cultural conservatives increasingly uncomfortable with consumerism and all that is solid melting into air, a new generation of muckrakers publicizing corruption in high places... I mean, I'd read it.)