By LESLEY CLARK

House Speaker Nancy Pelosi has endorsed three Miami congressional candidates after two House Democrats from South Florida refused to participate in their campaigns because of their friendships with the Republican incumbents.

Letters signed by five House Democrats, including some of Pelosi's closest allies, congratulated each of the candidates for a ''strong start'' to their campaigns and said they look forward to supporting the campaigns and helping each of the three ``become our newest Democratic partner for change in Washington.''

The letters to former Hialeah Mayor Raul Martinez, former Miami-Dade Democratic Party Chairman Joe Garcia and businesswoman Annettte Taddeo came in the wake of a Miami Herald story that detailed how two influential members of Congress said they would not support the three because of long-standing personal and professional relationships with the Republican incumbents.

Reps. Debbie Wasserman Schultz of Weston and Kendrick Meek of Miami, who both raise money for the Democratic Congressional Campaign Committee, said they would not campaign for the trio because of ties to Reps. Lincoln Diaz-Balart, Mario Diaz-Balart and Ileana Ros-Lehtinen.

Democrats say they may have their best shot in years to unseat at least one of the three, and word that Wasserman Schultz and Meek would be on the sidelines infuriated party activists, including Dade Democrats who voted Monday to ``pledge support behind the three.''

`WE ARE PROUD'

Wasserman Schultz is a co-chair of the Democratic Party's ''Red to Blue'' program, which raises money and mentors top candidates, and the letter is aimed at tamping down any suggestion that there won't be national party support for the three Miami challengers.

''We are proud of what you have achieved in this early stage and look forward to working with you to meet the critical changes ahead,'' the letter, written on Democratic Congressional Campaign Committee stationary, says. In addition to Pelosi, signers include Majority Leader Steny Hoyer, Majority Whip James Clyburn, Democratic Caucus Chair Rahm Emanuel and DCCC Chair Chris Van Hollen.

Meek said neither he nor Wasserman Schultz have sought to dissuade the three candidates from running and he called them ''excellent candidates that have a good chance at winning.'' He said both he and Wasserman Schultz will still be raising money for Democratic candidates nationwide.

Wasserman Schultz, who has told the party that another member of Congress should coordinate the local races, said Friday she encouraged the Democratic leadership team to send the letter.

''As a chair of the DCCC Red to Blue program, I have made clear to our Democratic leadership throughout this election season that the DCCC should be involved in these races,'' she said.

The prospect of a Democrat refusing to help fellow party members challenging Republicans created a firestorm on left-leaning blogs, which didn't go unnoticed by the Democratic Congressional Campaign Committee. Its official blog, The Stakeholder, noted earlier this week that the party had ``three strong Democratic challengers fighting for change against some of President Bush's most reliable rubber stamps.''

`FRUSTRATION'

It acknowledged the ''frustration'' with Wasserman Schultz, but said that "while some of our members may not always be able to actively campaign with every candidate, you can be assured that the DCCC will be there.''

''Rep. Debbie Wasserman Shultz works tirelessly to help elect more Democrats to Congress,'' the blog entry says. ``She has made clear that she supports the DCCC involvement in these South Florida races and has made sure that a member who could completely throw themselves into those races would be assigned to them.''

PLEASED

The candidates welcomed the letter.

''I have more confidence than ever that Debbie Wasserman Schultz and the Democratic Party are going to do what's in the best interest of the district and the nation,'' Garcia said. "I'm very comfortable with the strong support we are receiving from the national party.''

''You can't get any higher than this,'' said Martinez. ``This is the leadership I'll be counting on for guidance and support when I get to Washington.''