When incumbent state representativeDavid Rivera was unable to seek re-election in 2010 due to term limits, Núñez ran to succeed him in the 112th District, which included parts of Broward County, Collier County, and Miami-Dade County, stretching from Doral to Naples. In the Republican primary, she faced Juan D'Arce and James Patrick Guerrero, and campaigned on working to pass legislation to "improve the economy" and to "reform the Medicaid program in order to contain the ever-growing costs that affect taxpayers." Ultimately, Núñez won the primary over her opponents, receiving 66% of the vote to D'Arce's 19% and Guerrero's 15%. Advancing to the general election, she faced Sandra Ruiz, the Democratic nominee and a Doral City councilwoman, and Robert Van Name, an independent candidate. Núñez campaigned on job creation, noting, "For me, the most important issue for District 112 and in fact for the entire state of Florida is creating jobs, improving the economy and lowering the tax burden for businesses and property owners." The Naples Daily News criticized the nature of the district, noting, "If there is a textbook reason for redistricting reform, this race...would be it," and opined that "there is little sense of Collier connection from either Miami-based candidate." Despite this, they endorsed Núñez over Ruiz because Núñez met with the editorial board and Ruiz did not, which they noted was "a dreadful measuring stick for picking such a high-ranking public servant." Ultimately, Núñez won out over her opponents by a comfortable margin, scoring 56% of the vote to Ruiz's 39% and Van Name's 5%. When the state's legislative districts were redrawn in 2012, Núñez was drawn into the 119th District, where she opted to seek re-election. She was challenged in the Republican primary by Libby Perez, but easily won renomination with 73% of the vote. Núñez only faced write-in opposition in the general election and easily won re-election. During the 2014 legislative session, Núñez worked with state senator Jack Latvala to sponsor legislation that "would allow the children of undocumented immigrants to pay the same in-state tuition rates for college as other Floridians," which ended up passing the legislature. As reported by The Hill in 2018, Jeanette Nuñez will introduce legislation in Florida "to standardize daylight saving time for the entire calendar year". To make the "Sunshine Protection Act" nationwide, Senator Marco Rubio would sponsor such a bill in the Senate given the bill could not take effect until the federal government makes the change. This is because the "provision would shift the state into a different time zone permanently", something which requires a federal regulatory action or an act of Congress.
Lieutenant governor of Florida
Selection
On September 5, 2018, then-congressman Ron DeSantis selected Núñez to be his running mate in the 2018 Florida gubernatorial election, facing off against Andrew Gillum and running mate Chris King. DeSantis and Núñez would go on to win the election by a margin of less than half of a percentage point. Núñez is the first Hispanic woman to serve as lieutenant governor of Florida.
Tenure
Núñez was sworn in as lieutenant governor on January 8, 2019, succeeding Carlos Lopez-Cantera. During her time in office, she has mostly been known for her support for exiles of Venezuela, hosting various roundtables and events in an effort to find ways of helping them.