The South has struck me as socially conservative, but economically liberal. That is starting to change more now.
In the late 1800's, there was a split with the Republicans. There were a new branch that were gaining more influence. They were I believe considered "Liberal Republicans". Liberal then meant Lockean Liberal, or is today known Classical Liberal. Largly libertarian. The other branches were the Thaddeus Stevens Radicals, Free-Soilers(out west) and then were the Old Whigs, Temperence, "Know-Nothings", and such from the Northeast Protestants.
The democrats were dominated by the Old South and Catholics(in response to Know Nothings), especially the Irish.
I think that Wilson was the dem that really started to tilt left. Cleveland if I remember right, was very conservative. Coolege was a rarity, a Mass Conservative.
As for Wilson, you won't hear a lot from him on this forum from southerners because Wilson grew up in Virgina at the end of the civil war. One of his earliest memories was seeing Jefferson Davis being taken away by the union army. Wilson was a proud confederate and really loathed Lincoln most of his life, so the Lincoln-haters on FreeRepublic don't want to admit that one of their own actually passed most of the federal laws they're trying to blame Lincoln for (example: the "income tax" that Lincoln passed was temporary and always designed that way, whereas the income tax Wilson gave us was permanate and specifically designed to stay in place today, which happened)
I would also point out that the socialists in the Democratic Party had control of many local organizations before Wilson brought it to the national level. The Illinois Democrats were undoubtedly socialist-leaning in the 19th century. Our governor in the 1890s was a fellow named John Peter Altgeld . Historians actually rank his as one of the two most liberal governors we've even had, perhaps even worse than Otto Kerner (a Daley-machine canddiate and FDR clone in the 1960s who went to prison for massive corruption). Altgeld was the notorius Chicago judge who controlled a giant labor union movement and sided with the infamous haymarket strikers. He passed so much state "regulations" over business that he was overwhemingly defeated in the next election by a conservative Republican. As you mentioned, President Clevland controlled the national wing of the Democratic party, and despised Altgeld. However, Altgeld had a lot of influence over the party leaders and definitely got the party to nominate more liberal candidates. Clevland wouldn't endorce his own party's nominee (William J. Bryan) to suceed him because the guy was far-left on economic issues. Cleveland endorced the Republican party nominee (McKinley), because he considered him a "sound money man".
Finally, I should point out that the GOP in the 19th century took a while to find it's ideological focus. It really started out as a single-issue party in 1854 who's sole plank was opposition to the spread of the slavery. Thus, every anti-slavery person, REGUARDLESS of the ideology, joined the GOP. Conservatives, Liberals, Libertarians, centrists, and Pat Buchanan style right-wing "populists" (the Know-Nothing who joined the GOP) were all aboard early on. The party ran a very liberal candidate in it's first presidential election (John Fremont), and he worried people because he was consided a "radical". The responce in the next election was to try and find a middle-of-the-road Republican, and the result was Abraham Lincoln (far from the "marxist" paint that the hate-Lincoln crowd tries to paint him as). With the "radical" (liberal) Republcians kicked out of the party during recostruction, I believe conservatives had marginal control over the GOP by 1876 and have held on to it (with a few exceptions) even since then. When the GOP strayed from it's norm in the late 1880s and once again nominated a libearl Republican ('progressive' James G. Blaine), the conservative Republicans abandoned their party and used enough influence to talk the Democrats into selected a conservative that they would vote for (Cleveland). Conservative Republcians were certainly a reconizable force in the 19th century, they were known as "Mugwumps".
So, IMO, this is why we should ignore freepers who scream that the Republicans were the "liberal" party and the Democrats were the "conservative" party only a generation ago. Most of these so-called "historians" are just citing something their yellow-dog Democrat granddaddy told them. The south may have broke with the Democrats in the 60s and 70s because they were socialists, but alot of the nation figured that out long ago. ;-)
P.S. Franklin Roosevelt was the Dem party nominee for VICE President in 1920, so Al Smith's nomination in 1928 was certianly the exception rather than the rule.