Smith lost badly in 1928, but it wasn't a total blowout. Hoover won by a nationwide popular vote margin of 17.4%. However, Smith was the first Democratic presidential candidate since Wilson in 1916 to get over 40% of the vote. He nearly doubled the raw vote total of the 1924 nominee, about 15 million as opposed to about 8 million.
In 1932, Roosevelt got 57.4% of the nationwide popular vote, with almost 23 million votes and an 18.8% margin over Hoover.
Since all the issues have turned Smith's way between 1928 and 1932, I think he wins in 1932, but its just a closer rate. I think he does about 5% worse than FDR and Hoover does about 5% better. It appears this doubles both the number of states Hoover carried, from six to twelve, and also his electoral vote total, from 59 to 118.
None of the additional 1932 Hoover states are in the South, and only one, Kansas, is sort of in the West. In 1928, Hoover carried six Confederate states and Smith carried Smith, counting Oklahoma, which Hoover won in a landslide, as a Confederate state. None of the Confederate states were close in 1932. In 1928, Texas was close, and Hoover carried only Florida and Oklahoma by more than 10% of the vote. In 1932, the closest former Confederate state was Tennessee, which Roosevelt carried with a margin of 34%. Roosevelt carried Oklahoma by 47%; Hoover in 1928 carried it by 28%. I suspect some Democratic state parties in the South were secretly aiding Hoover. I don't think that happens in 1932 with a second Smith run.