In a referendum held on July 10, 2005, Puerto Rican voters approved the change to a unicameral legislature by 456,267 votes in favor, versus 88,720 against. (Voter turnout was 22.6% of the electorate.) However, another referendum would have to be held to approve the specific amendments to the Constitution of Puerto Rico that are required for the change. The House of Representatives let the bill die, though, so the changes were not realised. Had the changes been approved, the legislature would have become unicameral from 2009 onwards.
The Puerto Rican Independence Party supported the victorious Yes vote in favor of one chamber for the Puerto Rico Legislature. The Popular Democratic Party did not take an official stance on the matter and various of its leaders varyingly supported or opposed the measure. The New Progressive Party opposed the constitutional amendment under electoral review but, nevertheless, supported abstention from the vote.