BY LESLEY CLARK AND ERIKA BERAS

Joe Garcia, the brash Democratic strategist and former director of the Cuban American National Foundation, officially announced on Thursday that he will challenge U.S. Rep. Mario Diaz-Balart in the November election, setting the stage for a second South Florida grudge match.

Surrounded by family and supporters, Garcia made the announcement at a Best Western in Kendall.

''I'm here to effect change,'' he said in rattling off a host of issues that ranged from the environment to the economy, from the Iraq war to Cuba.

On the environment: ''We live in a district that embodies the environmental conflict that we face every day,'' he said.

On the economy: ''Some of you have to decide whether to fill your gas tank or fill your refrigerator,'' he said.

On the war: "We need to bring an end to the Iraq war.''

On Cuba: "I believe in keeping the embargo.''

His entry into the congressional race comes on the heels of former Hialeah Mayor Raul Martinez's decision to take on Diaz-Balart's older brother, U.S. Rep. Lincoln Diaz-Balart.

The contests -- the first serious challenges for the Cuban-American Republican incumbents -- reflect a Democratic Party emboldened by gains in 2006 that is now looking to target congressional seats long considered reliably Republican.

In an interview with The Miami Herald before the announcement, Garcia said: "This is a unique time in American history and just sitting on the sidelines and cheering isn't enough. People of good conscience have to provide leadership and that's something we're sorely lacking in South Florida and have been for a long time.''

Garcia said he plans to relinquish his post as chair of the Miami-Dade County Democratic Party to run for the seat.

Diaz-Balart, who was elected to Congress in 2002 from the western Miami-Dade congressional district he helped create as chairman of the state House's redistricting committee, said in an e-mailed statement that he welcomed the challenge. He faced minimal opposition in 2006 and ran unopposed in 2004.

''Elections are a wonderful part of the democratic process,'' the statement said. ``As I have always done, I will base my campaign on my extensive record of cutting taxes on our families and small businesses while delivering hundreds of millions of dollars in federal funding for our community's needs, including transportation, healthcare and education.''

Rep. Ileana Ros-Lehtinen, the third Cuban-American Republican from Miami, is also expected to draw a challenger.

The races are likely to be seen as testing a theory that a younger generation of Hispanic voters is more interested in domestic issues than ousting Fidel Castro.

Lincoln Diaz-Balart has told The Miami Herald and El Nuevo Herald that the challenge is part of a ploy by Castro sympathizers to lift or weaken the U.S. trade embargo against Cuba.

Garcia said the remarks are an effort to deflect attention from the lawmakers' records. He and Martinez say they support the embargo, but oppose the restrictions on family travel to Cuba that the Bush administration imposed in 2004.

"What the Diaz-Balarts call a 'global conspiracy to lift the embargo' in the United States is called an election for Congress and it happens every two years and thank God for that,'' Garcia said. "This is about the district, its people and who can better represent them in Washington. This is about healthcare, jobs, the economy. The real issues in the district.''

The district, which sprawls across western Miami-Dade and over to Naples, leans Republican, though the cushion has narrowed since 2002.

It also has the least number of Cuban Americans of the three South Florida Hispanic districts, but observers suggest Garcia may have a tougher time gaining traction because he lacks name recognition and the political base that Martinez built as mayor. Mario Diaz-Balart already has more than $465,000 in his campaign account.

''The district is probably slightly better for Democrats than Lincoln Diaz-Balart's district, but it's going to be hard for Democrats to wage war on two fronts in South Florida,'' said David Wasserman, congressional analyst for the Cook Political Report. ``Clearly the heavyweight battle that everyone is waiting to see is Raul vs. Lincoln, and I think this is really sort of the undercard.''

But the Democratic Congressional Campaign Committee suggests it may have a chance in a presidential election year, particularly one that has already produced record turnout.

''There's really a three-front dynamic in South Florida,'' said committee spokeswoman Kyra Jennings, noting the trio of Cuban Americans often votes together -- and even issues joint press releases.

Garcia would have to move into the district from his home in Miami Beach. But he says that he went to school in the district.

Garcia led the Cuban American National Foundation from 2000 to 2004, a tenure that included the defection of more than a dozen members who split to found the rival Cuban Liberty Council, an unabashedly hard-line organization.

But moderates credited Garcia with making the foundation approachable to newer waves of Cuban exiles, who are at times at odds with the historic exile community.

He left the group in 2004 to head up Hispanic voter outreach efforts for NDN, the New Democrat Network.

Garcia lost a 1993 bid for a seat on the Miami-Dade County Commission to former Commissioner Miguel Diaz de la Portilla. He was later appointed by former Gov. Lawton Chiles to the Public Service Commission and was installed as its chairman in 1999.