Two top Democratic targets could be in serious trouble, a new poll conducted by a Democratic-leaning firm shows. And the fact that both districts, represented by Republican brothers Mario and Lincoln Diaz-Balart, are majority Cuban suggests yet another historically Republican voting bloc could be ready to shift their alliances toward the Democratic Party.

The survey, conducted by Bendixen & Associates, polled 350 voters in Florida's Eighteenth, Twenty-First and Twenty-Fifth Districts 6/6-22, an admittedly long time to conduct such small surveys. The margin of error on the poll was +/- 5%. In the Eighteenth, Bendixen tested Rep. Ileana Ros-Lehtinen against businesswoman Annette Taddeo; in the Twenty-First, Lincoln Diaz-Balart and former Hialeah Mayor Raul Martinez were tested; and in the Twenty-Fifth, the pollsters asked about Mario Diaz-Balart and former Miami-Dade Country Democratic chairman Joe Garcia.

General Election Matchups
Ros-Lehtinen......58
Taddeo...............31

L. Diaz-Balart......41
Martinez..............37

M. Diaz-Balart......44
Garcia..................39

That two incumbents who have historically won by such wide margins -- Lincoln's 59% and Mario's 58% in 2006 were their lowest performances of their careers -- are in trouble speaks volumes about the trouble Republicans are in. Both districts are dominated by Cubans; the Twenty First, east of Miami stretching from Pembroke Pines to south of Hialeah, is 70% Hispanic, and the Twenty Fifth, which contains most of Miami-Dade County and two other counties farther east, is 62% Hispanic.

Democrats are thrilled with both of their candidates, each of whom have been named to the party's Red to Blue program. The new opportunities for the party to appeal to Cuban voters, who have cast reliably Republican ballots since the 1960s, open up all three southern Florida seats to Democrats. Still, Ros-Lehtinen's Eighteenth District, which contains much of Miami south through the Florida Keys, looks safer for Republicans.

Republicans have already pointed out that Bendixen & Associates is a firm affiliated with Democratic candidates. That's true; the pollster worked for Hillary Clinton's campaign during the primaries, though they are not working for any of the candidates running this year. It's a well-respected firm, though, and has a reputation for specializing in polling Hispanic voters.

David Hill, a prominent Republican pollster who deals with both Diaz-Balarts, told McClatchy that his polls show Lincoln leading Martinez by twelve points, while Mario's campaign manager said it was "comforting" that his candidate led even in a Democratic-leaning poll. National Republicans have added both incumbents to their Regain Our Majority Program, and they have more cash on hand than their challengers. Still, it's not a race either should, or will, take lightly.