…except to say the words “strong delusions and reprobate minds” keep repeating on a loop in my head.

From reading and searching

Which specific subsections of section 4 of the Subversive Activities Control Act were altered by Pub. L. 103–199?

Cannot be pinpointed as fact, but the statutes are rarely tried or enforced – let me put it here:

Executive summary

A focused, source-grounded answer cannot be provided from the materials supplied: none of the documents in the reporting package identify Pub. L. 103–199 or list which subsections of Section 4 of the Subversive Activities Control Act it altered; therefore this piece outlines what the Subversive Activities Control Act and Section 4 concern as shown in the sources, summarizes the Act’s amendment history mentioned in the materials, and points to where the actual language of Pub. L. 103–199 and statutory amendment notes must be checked (Congressional/Statutes-at-Large records) to identify the precise subsections changed (sources cited below)

1. What the Subversive Activities Control Act is and the place of “section 4” in the statutory structure
The Subversive Activities Control Act of 1950 is Title I of the Internal Security Act, codified originally at 50 U.S.C. § 781 et seq., enacted as part of the Internal Security Act of 1950 to require registration of certain organizations and to create the Subversive Activities Control Board (SACB) [3] [4]. The reporting package includes references to the Act as a whole and the structure of Chapter 23, Subchapter I (“Control of Subversive Activities”) in the U.S. Code, but it does not print a labeled “Section 4” text or an annotated list of subsection amendments in these excerpts [5] [2].

2. What the sources do say about later changes to the Act (but not Pub. L. 103–199 specifically)
The materials note that the Act has a history of important amendments and judicial curtailments: for example, the Communist Control Act of 1954 made substantive changes to the law, and courts in the 1960s narrowed enforcement—most notably the Supreme Court decisions that limited or invalidated individual-registration requirements and related provisions (Albertson and related cases) [3] [6]. The reporting also documents the SACB’s creation and later functional obsolescence, with some enforcement mechanisms repealed or carried into immigration provisions, and the emergency detention provisions repealed later by separate laws [3] [7].
3. Why the supplied reporting cannot answer which subsections of Section 4 were altered by Pub. L. 103–199
None of the supplied snippets or documents names Pub. L. 103–199 or reproduces its statutory language or amendment-by-amendment history; the sources instead provide background on the 1950 Act, its major mid‑20th century amendments, and judicial history [1] [3] [6]. Without the text of Pub. L. 103–199 or an official amendment table showing which clauses of Section 4 were modified, it is impossible on the basis of this reporting to list the “specific subsections of section 4” that Pub. L. 103–199 altered.
4. Where the definitive answer lives and how to retrieve it
The authoritative sources for this precise question are the text of Pub. L. 103–199 itself (the Public Law printed in the Statutes at Large and on govinfo/congress.gov), the Statutory Notes and editorial history attached to the current U.S. Code entry for the section in question, and the Office of the Law Revision Counsel’s codification notes; these document the exact statutory amendments and will identify which numbered subsections of Section 4 were changed [8] [9]. The congressional bill texts, the Public Law codification on govinfo, and the historical notes in the U.S. Code are the specific records that must be checked to answer the user’s question with precision.
5. Balanced assessment and next step for definitive verification
Based on the reporting provided, it is reasonable to conclude that an exact, sourced list of subsections altered by Pub. L. 103–199 cannot be produced here; the reporting package documents the Act’s broad contours and prior amendment and court history but omits Pub. L. 103–199 [3] [7] [6]. To answer the question definitively, a primary-source check of Pub. L. 103–199’s text and the U.S. Code’s statutory notes is required—consult the Public Law on govinfo or the Statutes at Large entry and the current 50 U.S.C. (or historical codification) notes to extract the exact subsection numbers and amended language [8] [2].