The party violated the Constitution and federal voting laws by taking away Florida Democrats' ability to have a say in choosing the presidential nominee, says the lawsuit filed by Sen. Bill Nelson and Rep. Alcee Hastings against the Democratic National Committee and Chairman Howard Dean.
"For the DNC to say to the fourth-largest contingency of Democrats in the nation that their votes will not matter in next year's presidential primary is not only shocking and ironic, but we believe is illegal," Hastings said at a news conference in Washington.
The national party's rules committee voted to take away Florida's 210 delegates after the state party chose to go along with a Jan. 29 primary. That date was set by Florida's Republican-led Legislature and signed into law by Republican Gov. Charlie Crist.
Democratic Party rules say states cannot hold their 2008 primary contests before Feb. 5, except for Iowa, Nevada, New Hampshire and South Carolina.
Nelson said they tried to compromise with party leaders before filing the lawsuit. "We didn't have any other choice," he said.
The calendar was designed to preserve the traditional role that Iowa and New Hampshire have played in selecting the nominee, while adding two states with more racial and geographic diversity to influential early slots.
Meanwhile, South Carolina Democrats will decide within two weeks whether to ask national party leaders to move the state's primary to Jan. 19 and make it the party's first contest in the South.
That would move the state out of Florida's shadow. South Carolina Republicans already have decided to vote Jan. 19.
"The concern is we don't want to be 10 days after the Republican primary," Joe Werner, the state Democratic Party executive director, told The Associated Press on Thursday.
The Iowa and New Hampshire congressional delegations on Thursday sent a letter to House leaders asking them to stay out of the simmering fight over primary election dates.
"Constitutional questions have already arisen related to congressional action to set the order of presidential primaries and caucuses," the letter said. "We believe that this matter is best left to the two major political parties and the states."
The lawsuit filed by the Florida lawmakers in Tallahassee said, "For the right to vote in a presidential primary to have any meaning, those presidential primary ballots must result in votes that are going to count at the party's national convention."
It notes the controversy over vote-counting in Florida that extended the 2000 presidential election, which was decided only after a Supreme Court ruling.
"In the aftermath of the shattering events of 2000, Democrats here and around the country have made continued efforts to assure that every vote counts," it said. "It is thus truly a monumental irony for the Democratic National Committee to replace its own commitment to assuring that every vote must be counted with a decree that no Florida Democrats' vote will count."