Unlike the 25th, the 21st has long been considered the most Republican district in the Miami area. No other party even put up a candidate when filing closed on April 30, handing the seat to Díaz-Balart. Díaz-Balart was reelected unopposed in 2012 in the renumbered 25th district. In 2014, Díaz-Balart ran unopposed. In 2016, Díaz-Balart beat Democrat Alina Valdes by a margin of 62.4% to 37.6%. It was only the third time that a Democrat had even filed to run in this district, which had been numbered as the 21st from 1993 to 2013. The "Miami Herald" reported in April 2018 that Díaz-Balart seemed a shoo-in for re-election in November. Former Hialeah mayor Raúl Martínez, a Democrat who had challenged Lincoln in what was then the 21st in 2008, said the 25th district "is very hard to win for a Democrat, especially if you're not Hispanic and you don't speak Spanish." Valdes, who had lost to him in 2016, was a candidate in the Democratic primary. In April, Annisa Karim, who is active in the Democratic Party, announced that she, too, would run in the primary. In May, the "Herald" reported that Mary Barzee Flores, a former judge who had at first decided to run in the 27th district, had opted instead to run for Díaz-Balart's seat. In the November 2018 general election, Díaz-Balart defeated Barzee Flores, winning 60.5% of the vote to her 39.5%. As of January 2018, Díaz-Balart had voted with his party in 92.4% of votes so far in the 115th United States Congress and voted in line with President Trump's position in 93.1% of votes. He is a founding member of the Congressional Hispanic Conference, a caucus of Hispanic Republican congressmen. In May 2019, Díaz-Balart voted to prohibit discrimination on the basis of sexual orientation and gender identity in employment, housing, public accommodations, public education, federal funding, credit, and the jury system under the Equality Act. He joined seven other Republicans and 228 Democrats in supporting the legislation, which passed the United States House of Representatives during the 116th Congress. According to Vote Smart's 2016 analysis, Díaz-Balart generally supports pro-life legislation, opposes an income tax increase, opposes mandatory minimum sentences for non-violent drug offenders, opposes federal spending as a means of promoting economic growth, supports lowering taxes as a means of promoting economic growth, opposes requiring states to adopt federal education standards, supports building the Keystone Pipeline, supports government funding for the development of renewable energy, opposes the federal regulation of greenhouse gas emissions, opposes gun-control legislation, supports repealing the Affordable Care Act, opposes requiring immigrants who are unlawfully present to return to their country of origin before they are eligible for citizenship, opposes same-sex marriage, and supports allowing individuals to divert a portion of their Social Security taxes into personal retirement accounts.