With some context it's a bit easier to make sense of the original example:
The public outcry against the speculators grew louder and more venomous.[...] Against no one was feeling more bitter than against Rhett Butler.
The subject of the bolded clause is the noun phrase feeling which refers to the public sentiment. The structure of the sentence is complicated by the fronting of the negative adjunct (read 'adverbial') Against no-one.
Because this negative adjunct has the effect of negating the whole sentence, it causes compulsory subject-auxiliary inversion. For this reason we see the Subject feeling occurring after the verb was instead of before it:
- Against no one was feeling more bitter than against Rhett Butler.
We can compare this with the ungrammatical example below:
- *Against no one feeling was more bitter than against Rhett Butler.
Of course, because the noun feeling has an -ing ending, it's occurrence after the verb was makes it look a bit like it's part of a past continuous construction, and this makes the sentence a bit more difficult to intuitively analyse.