"...for whatever the Prohibition Party had hoped to accomplish, the lack of a full wartime ban as they had hoped for proved there were limits to what they could accomplish, and a powerful cross-partisan alliance of "wets" had formed by the end of the conflict to prevent anything even approximating it. It was true that Liberals were, on general, much more likely to support prohibition east of the Mississippi while support for temperance was fairly bipartisan to its west; it was also the case that most Western states, with the exception of California and Oregon, had entered the Union with constitutional prohibition already built into their governing documents, or in the progressive spirit of the early 1910s drafted new constitutions that did so, such as in Dakota, Colorado, or even Midwestern Indiana. This created an ample block of drys in the Democratic ranks, but also a block who were less worried about passing a nationwide prohibition, as their states were already very prohibitive, and as 1918 came about the sense was increasingly on the Democratic side that the question of drink was one which badly split their party in an age (such as the case of Oregon, where feuding over it had become an internecine bloodbath) where they otherwise agreed on a great many things, in particular their contempt for President Root.
The votes were there for a law against alcohol at the federal level, but not a full constitutional ban, as the Prohibition Party had hoped, and Root, already embattled by the spring of 1918, elected to simply split the difference. The Milwaukee Beer Riots had badly burned his predecessor Hughes, who as a personal teetotaler felt much more strongly about the matter than Root ever did, and with enough on his plate - especially his much stronger opposition to women's suffrage, another parallel issue of the day - Root was unwilling to further damage Liberal prospects in strongly wet states like Wisconsin or his native by expending his political capital on a draconian Prohibition. The Liberal-controlled Congress thus pressed ahead with a bill that suited his views, as well as those of Democratic drys from the West, without offending wet Democrats and Liberal moderates on the question: the Interstate Liquor Control Act, which would govern American alcohol law at the federal level until its repeal in 1946.
The ILCA was composed of two parts, the Interstate Liquor Transport Regulation Policy and the Liquor Import Prohibition Policy, and they worked in tandem. Effectively, the ILCA did not ban the personal possession or consumption of alcohol, nor its production, as many drys had demanded, Rather, it made it a federal felony to transport liquor, wine or beer with an alcohol by unit content in excess of ten percent (modified to twelve percent in 1933) across state lines, regardless of whether the states it was moving between internally regulated or banned liquor. The import rules were even stricter - with the exception of light beer with an alcohol content of five percent or less, all alcohol was banned from being imported into the United States from neighboring countries or from overseas by train and boat or, by the late 1920s, by plane.
Temperance activists had spent decades building to this moment and thus were enormously frustrated; the ILCA did little more than make permanent the interstate commerce controls put in place during the war but relaxed a number of the Grain Board's restrictions on breweries and distilleries, and they were not wrong that the ILCA was a half-loaf compromise that only solved part of the problem. It was a mixed bag for Root; soft drys were generally happy with the Act, which the oft-Protestants viewed as largely targeting Catholics they did not trust or like, and the majority of them already lived in dry states in the West or New England. Midwestern wets were, by and large, fairly unaffected, and vibrant brewing and distilling economies exploded in places like Wisconsin, Illinois, New Jersey and New York where alcohol laws were fairly lax, at least as compared to Pennsylvania, Indiana and Ohio. But hard drys felt betrayed after years of building grassroots support through the Liberal Party, and many wets were skeptical that the ILCA would be the end of it. Politically, Root considered the ILCA the end of the war; for others, the battle had simply shifted back again to the states, this time with a growing "Liquor Control Agent," or "Lickies," often former veterans eager for work, supporting them to prevent transport across state lines and enforce the law federally..." [1]
- A Toast to the Devil: The Rise and Fall of Prohibition Politics
[1] So this is my long-previewed "split the difference" on Prohibition. Root IOTL was pretty skeptical of Prohibition compared to many of his peers so this seemed to fit his personality well, and without the South, the votes aren't there for Volstead/18A. This is still a pretty strong Prohibition in many ways, but well short of OTL, especially with a number of wet states - especially major ones like Wisconsin, Illinois and New York - redoubts of legal alcohol that can definitely avoid the Lickies as it fans out across the country surreptitiously