A trial over whether state legislators broke the law when drawing up new political maps began Monday.
A coalition of groups contends that the Florida Legislature in 2012 drew up new maps for congressional seats that violate standards adopted by voters.
Attorneys for the Legislature call the allegations false and say legislators followed the law.
The lawsuit says several districts, including the one held by U.S. Rep. Corinne Brown in Jacksonville, were drawn in a way to help Republicans because legislators packed Brown's district with Democrats.
Voters in 2010 passed the "Fair Districts" amendment that says districts cannot be drawn in a way to favor incumbents or members of a political party.
Top legislative leaders are expected to testify during the trial.