To understand the demographic shifts of Florida's growing Hispanic vote, you need only look to South Florida, where three congressional districts long dominated by registered Republican voters are being crowded by out by more Democrats and independents.
Tallahassee has taken notice. This week, legislators approved a redistricting plan that would offer safer and stronger districts for Miami's three Cuban-American Republican lawmakers, U.S. Reps. Mario Diaz-Balart, Ileana Ros-Lehtinen and David Rivera.
Since 2002, the last time legislators reconfigured the political districts to reflect the new census data, the number of registered voters has soared in their districts.
Growth has been particularly strong among non-Cuban Hispanic voters, the majority of which have registered as independent, no party affiliation or Democrat, political analysts say.
The results have Democrats salivating while Republicans, armed with new maps, remain confident they will retain their stronghold.
"Miami-Dade is not staying with three Republican Congress people,'' predicts Christian Ulvert, a Miami-based Democratic political consultant. "With Miami's population changes, and the fact that Hispanics tend to be trending more Democratic, that could prove problematic for them."
Ros-Lehtinen dismissed the notion that a demographic shift will hurt Republicans. She said she's been hearing the same argument since taking office in 1989 following the death of legendary Democratic congressman Claude Pepper.
"I guess if they repeat it often enough, they might believe it," she said.
Still, the makeup of Ros-Lehtinen's current District 18 illustrates that things may not be the same, anymore. Her district, which stretches from Key West up the coast to the Broward County line, grew by 58,699 voters since the 2000 census. But 61 percent of the newcomers registered as no party affiliation; 26 percent registered as Democrat; and, Republican registration dropped 3 percent.
The result: a district where Republicans went from a 69,000-vote margin to one where the GOP margin was only 745 voters.
Florida's Republican-led Legislature hit the reset button with the once-a-decade redrawing of political maps and approved a map that strengthens Ros-Lehtinen's staying power. Her newly-drawn district shrinks dramatically in size as she loses the Keys and the more liberal strongholds of Miami Beach, but the district's Republican to Democrat voter advantage climbs ten-fold.
"I'm proud to represent any area that the Legislature gives me,'' Ros-Lehtinen said last week. She said she will be reluctantly giving up the Keys and Miami Beach but she'll return to representing Hialeah, home to her first state legislative district.
The new proposed maps also help Diaz-Balart, himself a former legislative redistricting chairman. In the last decade, his current District 21 saw a 26 percent increase in registered voters and the Republican to Democrat voter margin of 29,000 voters shrunk to 6,000 votes by 2012.
Diaz-Balart's new district sheds voters in University Park, Kendall and Country Walk. It becomes more rural, moves west over the Everglades, north through Immokalee and up to LaBelle. And the new map gives the congressman 24,000 more registered Republicans than Democrats.
This week, only moments after the Legislature approved its redistricting maps, the Democratic Party and a coalition of voting groups challenged the proposed political boundaries.
"Unconstitutional gerrymandering,'' claims the lawsuit filed by the coalition of voting groups that backed Florida's new redistricting standards.
Under the constitutional guidelines, legislators are banned from intentionally protecting incumbents or political parties and the complaint singles out Diaz-Balart's district as one of the ways lawmakers "undermine the voters will."
The lawsuit by the Florida League of Women Voters, the National Council of La Raza, and Common Cause of Florida, alleges Diaz-Balart "took affirmative steps to influence members of the Legislature and its staff to 'improve' the composition of their new districts and make them more favorable."
Diaz-Balart calls the claims "absolute and total fabrication." He says he hasn't spoken to anyone in the Legislature about making districts more favorable to himself or anyone else — and neither have his staffers.
Rivera's newly drawn district, by contrast, is not as helpful to his political prospects as it is to Diaz-Balart's.
In the last 10 years, Rivera's District 25 — which stretches from Homestead, through Doral and across the peninsula to Naples —grew dramatically. The number of registered voters increased a whopping 41 percent from 2002 to 2012. Most of the new voters — 42 percent of them — registered as independent or no party affiliation. Meanwhile, 36 percent registered as Democrat and 20 percent registered as Republican.
Diaz-Balart held that district until 2010, when he left it to move into the district held by his brother Lincoln Diaz-Balart, who retired after 18 years in Congress. He had seen the trend: in 10 years the Republican voter advantage went from a 21,000-vote margin to a 3,000-vote edge.
The new congressional map gives Rivera a slim 4,000 Republican voter margin and now picks up the Keys. Voters in the district supported John McCain over President Barack Obama by a fraction of a percentage point and supported Gov. Rick Scott over Democratic challenger Alex Sink by an even smaller amount.
"We could see (Rivera) being challenged both in a primary and from whomever the strongest Democrat candidate in South Florida is,'' said Sean Foreman, associate professor of political science at Barry University, noting that Rivera is the only one of the three to face a challenger, state Democratic Rep. Luis Garcia of Miami Beach.
"But one has to be careful,'' Foreman added. "David Rivera is a very tough politician and he knows how to mobilize.''
As for the South Florida House districts now represented by the three Cuban-American Republicans, Foreman and Ulvert both say that in 10 years Miami's congressional delegation will have more Democrats. But, Foreman believes, it "will remain safely Republican for some time."
"It doesn't look good for Democrats partly because of the way the lines are drawn but partly because of the candidates,'' he said. "There's nobody on the bench ready to jump in and take on the Republican juggernaut for Congress.''
That juggernaut, Foreman explained, includes Cuban super voters, "older Cuban-Americans who are passionate about getting their like-minded representatives in office,'' who turn out reliably and vote consistently for Cubans. Democrats have a two to one registration advantage over Republicans in Miami-Dade but Cuban super voters have "helped Republicans dominate in local, state and federal elections,'' he said.
Miami-Dade's population may grow and voter registration may shift, Foreman said, "but the old card of anti-Castro, anti-Cuba still works in 2012."
Miami Herald State and Politics Editor Sergio Bustos contributed to this report. Mary Ellen Klas can be reached at meklas@MiamiHerald.com and on Twitter @MaryEllenKlas