The political landscape is shifting in three Miami-area congressional districts held by powerful Republicans, according to voter registration figures that show Democrats making sizable gains.
According to county and state tallies, the number of registered Republicans in the three districts, while still larger than registered Democrats, has declined since the last congressional election in 2006, while more Democrats have been added to the rolls.
''There is clearly a move toward the Democrats that's undeniable,'' said Democratic strategist Jeff Garcia, who helped convince former Hialeah Mayor Raul Martinez to challenge Rep. Lincoln Diaz-Balart in a matchup viewed as the headliner among the three.
''Clearly something's happening here,'' Garcia said. ``There's tremendous dissatisfaction with the president and congressional leadership and it's showing up in the numbers.''
Republicans still hold the edge in all three districts, and Carlos Curbelo, a spokesman for the Diaz-Balarts, suggested a ''silver lining'' for Republicans is an uptick in GOP voters since the beginning of 2008. Unlike Democrats, Republicans had a hotly contested presidential primary in late January.
It's not clear yet whether the shift is enough for any of the seats to switch to the Democrats. But the boost comes as Democratic numbers have surged in a number of states, fueled by the competitive presidential primary. Garcia notes that Florida numbers are up even though the state's Democratic presidential primary in January was rendered officially meaningless by the national party.
As of April 1, Diaz-Balart's district -- which includes parts of Miami-Dade and Broward counties -- had dropped 3,576 Republicans, but picked up 5,414 Democrats, compared to 2006. The district now has 125,726 Republicans and 106,570 Democrats.
In Rep. Mario Diaz-Balart's district, which includes parts of Miami-Dade and Collier counties, registered Republicans were down 596, to 130,690, and Democrats were up 8,650, to 116,744.
And in Rep. Ileana Ros-Lehtinen's district, which includes South Dade and all of Monroe County, Republicans were down by 1,032 voters, to 127,250, while Democrats gained 7,712, to the current 113,112.
Curbelo suggested that all three GOP'ers have appeal beyond party lines, noting that they've outperformed the top of the ticket in previous elections.
''We're confident that voters will do as they always do and choose the best candidate, regardless of party affiliation,'' he said. ``They've consistently shown broad-based support from Republicans, Democrats and independents.''
Democrats believe they have their best shot in years at defeating the Cuban-American Republican trio in a race that is likely to test their belief that voters in the largely Cuban-American districts are more worried about housing foreclosures and affordable healthcare than toppling the Castro dictatorship.
Martinez, former Miami Dade Democratic Party chairman Joe Garcia, who is challenging Mario Diaz-Balart, and Annette Taddeo, who is taking on Ros-Lehtinen, all collected more money than their rivals in the fundraising quarter that ended March 31, though they trail in cash on hand.
''Running against incumbents is always difficult, but these are the biggest breaks a candidate can get that directly affect the outcome of an election,'' Jeff Garcia said.
Republicans note the races haven't made some rosters of competitive House matchups as rated by national political handicappers, suggesting some analysts are not yet convinced the Democratic campaigns are viable.
But Stuart Rothenberg, editor of the Rothenberg Political Report, which keeps tabs on competitive races, said he's watching the South Florida contests -- particularly the race between Lincoln Diaz-Balart and Martinez.
''Our view is that this is an interesting possibility for the Democrats, but we want to see more,'' Rothenberg said.
He noted that one factor in the races is the decision by Weston Democratic Rep. Debbie Wasserman Schultz not to actively campaign for the three Democrats because of her close relationships with the three Republican colleagues.
Wasserman Schultz, who co-chairs a national party effort aimed at helping House candidates, and Rep. Kendrick Meek, a Miami Democrat, have said they plan to stay neutral because of ties to the three Republican incumbents.
But Wasserman Schultz last month invited the Democratic trio to a Miami fundraiser, and national Democrats have sought to bolster their support for the three candidates.
The latest show of support will be a visit to Miami on Monday by Rep. Chris Van Hollen, the Maryland Democrat who chairs the House campaign committee. He plans to meet with local Democratic activists and talk up the trio's chances, said Kyra Jennings, a spokeswoman for the Democratic Congressional Campaign Committee.
''The DCCC and leadership believe these seats offer real opportunities,'' Jennings said.