S.B. No. 4 is a comprehensive bill that redefines the congressional districts in Texas for the election of members to the United States House of Representatives. It provides detailed descriptions of the geographic areas included in each district, specifying counties, tracts, and blocks. Notably, the bill introduces new legal language to establish definitions for terms such as "tract," "block group," and "block," referencing the 2020 Census TIGER/Line Shapefiles. Additionally, it allows for the inclusion of any erroneously omitted geographic areas into the appropriate district based on legislative intent, citing the case of Smith v. Patterson as a precedent.

The bill also supersedes all previous enactments or orders related to congressional districts in Texas, effectively repealing prior legislation, including Chapter 7 (S.B. 6) from the 87th Legislature. It specifies that the new districts will be applicable for the election of members starting with the primary and general elections in 2026, while ensuring that the current congressional districts remain in effect for the 119th Congress. The bill is designed to take effect immediately upon receiving a two-thirds vote from both houses or on the 91st day after the legislative session if such a vote is not achieved.