In 2010, Díaz de la Portilla was elected to the Florida Senate from the
36th district, which encompassed parts of
Miami,
Coral Gables, and the surrounding area, without general election opposition. Decennial redistricting renumbered his seat the
40th, and he was re-elected unopposed in 2012 and 2014. When the Florida Environmental Regulation Commission signed off on controversial limits for toxic compounds that can go into Florida's surface waters, Díaz de la Portilla called on Governor Scott to do a do-over and reconsider their position. In 2014, Díaz de la Portilla was downgraded to a "F rating" by the
National Rifle Association of America. On February 19, 2016, USF Executive Director and NRA Past President Marion P. Hammer sent a "Florida Alert!" to USF & NRA Members and Friends regarding de la Portilla's actions. Portilla rejected several key gun bills including HB4001, HB163, and SB68. When dealing with campus carry, Díaz de la Portilla took meetings with university presidents, college police chiefs, faculty members, and students from around the state. All of them voiced their opposition to the bill. It's not clear whether the bills would have passed had Díaz de la Portilla allowed them to come up for vote, but there were 26 Republicans and 14 Democrats in the Senate, and approval for either measure would have required only a simple majority. In an interview with Sun Sentinel reporter Dan Sweeney, Díaz de la Portilla stated, "I don't think I'm an anti-gun guy. I'm a pro-common sense guy." In April 2016, Díaz de la Portilla was recognized nationally by the American Psychiatric Association for championing efforts to address the need to improve mental health services in the Criminal Justice system in the state of Florida. Court-ordered redistricting in 2015 significantly altered the 37th district, making it more
Democratic. Díaz de la Portilla lost re-election in 2016 to Democratic state Representative
José Javier Rodríguez in the 2016 general election, 48.9 to 45.6%. ==Electoral history==