What you are looking for are resources on rhetorical analysis and/or rhetorical criticism. These are critical works that study a work of writing (written or orally delivered) not for its content but its structure, in order to elucidate how the author makes their argument compelling.
Rhetorical criticism is an ancient art, and the modern practices trace their roots to classical Greece and particularly to Plato. You'll find that summaries of the field often start here and then add in more modern approaches. It's also the reason most rhetorical devices have unnecessarily difficult Greek names, even in English discussions of literature.
I'm afraid I don't have firsthand experience with any significant teaching resources directly on the topic, but I did pick up some basics in many courses on ancient literature*, enough to point you in the right direction. Here are a few places I would recommend starting a search, especially since this seems to be a new discipline for you:
The Wikipedia page on Rhetorical Criticism gives a brief, basic overview of the different approaches to modern rhetorical criticism.
This Questia page on Rhetorical Criticism has a great summary of the discipline and its history, and it also also lists about 15 books and articles on the topic.
(If you want to compare books on the list, I'd recommend looking for book reviews. Here's a great resource on finding quality reviews of scholarly works: How do I find reviews? -- University of Chicago Library)
Brigham Young University has a nice website on rhetoric, Silva Rhetoricae
(Latin for "the Forest of Rhetoric"), which has a couple dozen pages introducing various concepts of rhetoric, and a long dictionary of rhetorical devices with examples.
You may be more interested in starting out with some basic lists or glossaries of rhetorical devices, which can help you get a good grasp on analytical definition and classification, and which are easier to navigate than a comprehensive dictionary full of unfamiliar terms. Rhetorical devices include structural devices, figures of speech, types of wordplay, different methods of exaggeration and repetition, and miscellaneous violations of logical grammar for effect. Once you know these terms and what they mean it will be much easier for you to seek out specific examples of each.
A few lists that include examples:
50 Rhetorical Devices for Rational Writing, By Mark Nichol
21 Rhetorical Devices Explained, BY PAUL ANTHONY JONES (Mental Floss)
30 Rhetorical Devices — And How to Use Them, Reedsy
*Classics programs embed some amount of rhetorical criticism in most courses because rhetorically rich, persuasive texts tend to survive better than others, and many of those that aren't Plato himself were involved in intertextual discourse with Plato and the Greek philosophers--even from centuries later and hundreds of miles away. Rhetorical training was also considered a significant part of a good education (for men, who were encouraged to be involved in the public and political spheres, and up until the 20th century, at least), so many artful political speeches, ancient and modern, display quite a bit of rhetorical skill. Any stylistic analysis of ancient writers will probably hold some interest for you, but that's not the first place I'd recommend you look.