Happy 100th anniversary of the American Prohibition!
I've a variety of scholarly work on the Anti-Saloon League's activities that went beyond lobbying government to ban booze - this included initiatives that were anti-union, anti-immigrant, and, some historians argue, in collaboration with the Ku Klux Klan. Its membership tended to reflect those sentiments.
How did this compare with the membership of the Women's Christian Temperance Union? Frances Willard, the founder of the WCTU, had a much more "do everything" attitude, which revolved around banning alcohol (and other stimulants), but also included women's suffrage and aspects of social reform and education to empower women (within the domestic sphere). "Americanization" was also a key component of their outreach to immigrants, especially when it came to consumption of alcohol.
This leads to my question: what was the WCTU's attitude toward including non-white, foreign born, Catholic, Jewish or poor women as active participants within the organization? Did any play a prominent or leadership role? If not, what role were they expected to play within the WCTU's structures? As influencers on the men in their families? Activists on the street? Something else?
For your first question, the WCTU's opinion on other social movements. As you mentioned, the social reform sentiment present in the WCTU was not nesissarry limited to alcohol, and many women did help with other social reform movements, one notable one being the poor. Francis Willard especially tried to evoke a more populist message that appealed to many regardless of social class, with a common message being "educated women educating other women", with more detail given in sources below. So generally, working class women could especially be keen to play a role in prohibition given the WCTU'S other platforms, including women's suffrage and general social reform. So working class women could especially play a part in influencing society.
The other issues you mentioned, most notably race and religion, things were a bit more complicated. Though Catholicism was often ok with alcohol, there were growing movements in Catholicism to adopt temperance to some extent, and Willard capatilized on this.
According to Ruth Bordin's biography of Willard, she made active outreach in the Irish Catholic community and had actually pushed for the resolution that allowed for Jewish and Catholic to work in the WCTU in 1895, although this was not nesissarily a popular decision within the WCTU by any means. Willard had actually used nativist rhetoric in some of their speeches from the time (her audience being white middle class women who had less than tolerant views towards Catholics and immigrants) but nevertheless saw base that Catholicism had to offer and tolerated the controversy. So while Jews and Catholics played a part in working in the WCTU they were far from totally accepted within the movement.
As for race, Willard and the WCTU did allow blacks to work within the organization, but not without controversy. As mentioned before, much of the WCTU was not nesissarily progressive, and also, according to "Ida: A Sword Among Lions: Ida B. Wells and the Campaign Against Lynching" Willard said the following:
The colored race multiplies like the locusts of Egypt," and "the grog shop is its center of power.... The safety of women, of childhood, of the home is menaced in a thousand localities
But this is not to mention the many black women who helped the WCTU cause by working with and inside of it, and the anti lynching mesure passed by the organization in 1893. But that being said, it remains likely that many members of the WCTU had doubts about the role blacks could play in their movement.
This is my first response on this sub, and I understand if this isn't the quality that mods are looking for, so please let me know if I did a good job and anything I can improve. I also understand if this warrents a deletion.
Sources
https://archive.org/details/temperancemoveme01blai/page/472
http://are.as.wvu.edu/willard.html#_edn35
Frances Willard House › HST...PDF Web results Frances Willard and the Woman's Christian Temperance Union, 1874 ...