Actually, the Klan's weaknesses were evident as early as 1924. To quote an old post of mine:
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Not having a Stephenson scandal would not IMO have saved the Klan.
The Klan had reached its peak and was starting to decline even before the Stephenson scandal hit in 1925. Already in 1924 it suffered such setbacks as the defeat of governor Walter Pierce in Oregon and the victory of "Ma" Ferguson over Klansman Felix D. Robertson for governor of Texas.
The Stephenson affair was not the only cause of the Klan's decline. Another important factor was internal dissension, both at the national level (the dispute between William Joseph Simmons and his successor as Imperial Wizard, Hiram Evans) and locally. (It is remarkable how in city after city, even before Stephenson was convicted, large numbers of the Klansmen--in some cities virtually all of them--seceded and formed new organizations like the Minute Men of America in Denver, the Independent Protestant Knights of America in Niagara, New York, etc. See Kenneth Jackson, *The Ku Klux Klan in the City, 1915-1930,*
https://books.google.com/books?id=xkgwSauBgTwC&pg=PA254 ) Another point is that electoral success became harder as the Klan's opponents united, and electoral frustration in turn led to decline in membership. (It also led non-Klan politicians who had associated themselves with the Klan to back away from it, so that joining the Klan would no longer bring patronage benefits.) Also, the Klan's issues became less compelling: Reds seemed less scary than in the early 1920s, immigration had already been restricted, Prohibition proved unenforceable, and the Catholic Church obviously was not going away. Finally, the sheer *novelty* of the group wore off--I think this factor is often underestimated. The 1920's was an era of short-lived crazes, and in some respects the Klan was one of them, though obviously more sinister than most. Even Al Smith's presidential candidacy in 1928 could not really revive it.
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I might have added that even the very narrow failure of the Democrats to denounce the Klan by name in their 1924 platform was not really a victory for the Klan; as Klansmen privately noted with concern, even many of those who succeeded in defeating the anti-Klan plank (like Bryan) made clear that they disagreed with the Klan.
Another thing to remember: As I noted at
https://www.alternatehistory.com/fo...ed-usa-looks-like.414958/page-2#post-14659501
"There really was no Klan position as such on most economic issues. Politicians who were members of or backed by the Klan ranged from ultra-conservatives to progressives like Hugo Black. Klansmen sometimes broke strikes and sometimes supported them.
"A lot of people are making assumptions based on an oversimplified image of the Klan as a tightly-controlled centralized organization imposing a "line" on every issue on everyone affiliated with it--like the Communist Party."
The Klan might support a national candiadte (like McAdoo in 1924) and he might win, but that would not be the same thing as Klan "control" of the government. McAdoo himself is a good example of this. The Klan supported him because he was pro-Prohibition and because his rivals for the Demcoratic nomination (Al Smith, of course but also Oscar Underwood) were so unaccepatable. But that hardly would mean that McAdoo if elected would be a tool of the Klan, as I explain at
https://www.alternatehistory.com/fo...gest-possible-kkk.422522/page-2#post-15484544