Evolution is indeed falsifiable, but nothing has been found that could possibly falsify it. Nothing short of finding real-life Shmoos would be enough to seriously damage it.
I am excited to see that you are a rhetorical scholar. That is also my profession. I think your statement is basically fair. That is the statement I keep reminding my creationist friends to keep in mind because I do get a sense at times that evolution is being revered more as a creed than a disclosure of the scientific process. If one is indeed open to the prospects of a theory of evolutioin being falsified, then it remains in a defensible domain of science.
In certain practical rhetorical functions it may necessarily be a creed but it is those functions that creationists, IDers, or various theist stripes are justly complaining about.