As the United States left WWI, Americans desired a return to the way the nation was before Progressivism. Warren Harding ran a successful campaign in 1920 by promising a return to normalcy; this soon became a buzzword for the era. One worry of the time was that immigrants from Eastern and Southern Europe would promote leftist ideas and would create a Communist Revolution. There was also some antisemitism with the movement as well. Congress passed quotas to largely keep out immigrants from Southern and Eastern Europe. There was also a Red Scare where the government looked to chase out Communists and anarchists. While this was eventually deemed unconstitutional, the movement did alarm many recent immigrants from Eastern Europe. The nativism movement of the 1920s even saw the renewal of the Ku Klux Klan.
Prohibition was passed largely as a patriotic measure in order to suppress German culture and to ensure a steady supply of wheat to war-torn Europe during WWI. Idealists such as Wayne Wheeler also claimed that the movement would be good for keeping the youth of America safe from alcoholism and ensuring that factories would be more productive as less workers missed work due to intoxication. This movement failed due to a lack of enforcement—the "normalcy" government of the three Republican administrations of the decade would not allocate adequate funding for the bill's enforcement. Also, the American people did not want the government telling them what they could imbibe. While the moralists of the country advocated temperance, most of America did not want this. There was also a push to get the United States back to Bible-based education as seen in the Scopes Monkey Trial where John Scopes was put on trial for teaching evolutionary theory, which at the time was illegal in Dayton. While he was found guilty, the trial became less a question of whether he broke the local statute, and instead became a question of whether the statute should exist at all. This was further evidence that the United States was trying get back to what it called the "good old days" when the United States was Protestant and temperate, when in reality this was not the reality for most Americans. While some believed in what the moralists wanted, most did not agree with everything.
I think that the issues of immigration, prohibition, and religion all fed into the rise of a reactionary, conservative element in the 1920s. The "Roaring Twenties" had cast its formidable impression on America as a cultural movement that praised the growth of celebrity, the notoriety of being infamous, and relaxed social expectations regarding behavior. Wider interpretation as to the social condition of women and people of color, along with a condition in which lawlessness was socially accepted and even encouraged had caused many Americans to flee to a more socially rigid form of identity. The desire for prohibition stemmed from here. Alcoholic consumption was seen as the cause of so much relaxation in social conventions, as it was the supporting cast for so much that made the time period "roar." The growth of organized crime and the establishment of the speakeasy was a part of this. The proponents of prohibition favored a temperance that sought to not only limit alcoholic consumption, but tighten the moral code that encouraged such a lifestyle.
In this desire for order and control is also where I think that one can see how a fear of immigration, in the form of the Red Scare, had been able to fester. The execution of Sacco and Vanzetti is representative of this fear of foreigners. Many Americans felt that the "Red Scare" was a rightful expression of the fear of communism. This fear translated into a growing resentment towards immigration, no longer seen as a strength, but rather as a potential for danger. Its limitation and curtailing was an attempt to impose control on something perceived out of control.
The craving for order and symmetry in a time period that had little of it helped to cause the rise of religious fundamentalism in the time period. The need for "old time religion," a brand of worship that was fundamentalist at its core, was one that arose from the perceived atheism and lack of spirituality that was so much at the core of social life of the 1920s. This filtered into many domains, as seen in the Scopes Monkey Trial. The battle between teaching evolutionary theory in the face of state law that demanded the teaching of a design of humanity as offered in the Book of Genesis highlighted how the rise of a literalist form of religion sought to construct order and rigidity in a social setting where it was noticeably absent.