The article establishes that the territorial legislature must be bicameral, and composed by the Senate as the upper house and the House of Representatives as the lower house. It also established the composition of each house, and that Puerto Rico must be divided into senatorial and representative districts for the purpose of elections. The article also established a board that must revise the districts after each decennial census so that they remain practicable, and divided upon the basis of population and means of communication. It also established how the number of members of each house must increase when a political party obtains more than two thirds of the seats in one or both houses. This was done in order to reduce the likelihood of one party having absolute control over constitutional amendments, as these require at least two thirds of the vote of each house in order to be enacted. Article Four was also very loose regarding the rules overseeing each house, establishing that each house must be the sole judge of the election, returns and qualifications of its members, that each house must choose its own officers, and that each house must adopt rules for its own proceedings appropriate to legislative bodies. This, in essence, gives broad powers to each house on how to structure itself and which procedures it must follow. It, however, established the posts of President of the Senate and Speaker of the House without any other specifics besides the title of the posts although interpretatively the article meant them to be the presiding officers of their respective house. The article also established that the sessions of each house must be open, what constitutes quorum, and where should they meet, namely in the Capitol of Puerto Rico. It also granted parliamentary immunity to its members. Article Four also established the parliamentary procedure to enact bills, namely that they must be printed, read, referred to a commission and returned therefrom with a written report, approved by the majority of which each house is composed, and signed by the governor in order to become law. The article also established the exclusive powers of each house, as well as establishing the post of Comptroller.
