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.