Díaz was one of three Democratic Senators, known as the "Gang of Three", who threatened to abandon the Democratic majority elected to the New York State Senate on November 4, 2008. A fourth, Senator-elect Hiram Monserrate, backed out of the group in early November. According to a memorandum leaked to the "New York Times" in December 2008, the remaining "Gang of Three" tried to use their leverage to have one of them named Senate Majority Leader and another named chair of the Senate Finance Committee, and to obtain a guarantee that the Senate would not vote on the issue of same-sex marriage. This deal fell through, and the three reached a compromise in which they recognized State Senator Malcolm Smith as Senate Majority Leader in January 2009.