Wallace wasn't a candidate of the city bosses. This post contains an abridged version of how Wallace could have gotten the nomination in 1948- without the bosses. https://www.alternatehistory.com/discussion/showthread.php?p=6573463&highlight=Hannegan#post6573463
Of course, FDR did effectively sell him out.
Wallace may have been naive in some ways, but he was not corrupt. That's one reason why I like him.
Even if Wallace would not have worked as well with Congress, he would have changed a lot of things for the better, IMHO.
I still need to do my TL where Wallace doesn't run in 48...