Lawsuits were first filed two years ago.
The trial is scheduled to start later this month in a dispute that could ultimately change the current makeup of the state's congressional delegation, where Republicans hold a sizable majority.
In an effort to speed up the 11-day, non-jury proceedings, both sides were allowed to give their opening statements Friday.
David King, an attorney representing the League of Women Voters and other groups suing the state, told Judge Terry Lewis that legislators used a "shadow process'' which allowed them to circumvent a constitutional mandate prohibiting legislators from drawing districts intended to protect incumbents or members of a certain political party.
King said evidence in the case will show that legislators were prodded by Republican consultants to increase the number of minority voters in the district represented by U.S. Rep. Corrine Brown, which stretches from Jacksonville to Orlando, in order to lessen the number of registered Democrats in other central Florida congressional seats.
"It was going to make a significant difference to these other central Florida districts,'' said King, who said four districts that initially leaned Democratic wound up getting split between Republicans and Democrats in the 2012 elections.
Every 10 years, lawmakers redraw legislative and congressional districts based on new population figures. Voters in 2010 passed the "Fair Districts'' amendments, aimed at preventing gerrymandering when districts are drawn.
King and other attorneys representing the plaintiffs said they plan to rely on emails and other documents from political consultants to assert that consultants, party officials and legislative staff worked in a way to draw maps favorable to Republicans.
They are also expected to put on the stand both Senate President Don Gaetz and House Speaker Will Weatherford, who were in charge of the redistricting process.
George Meros, an attorney representing the Florida House, called King's assertions a "fascinating story'' but said "it would not be supported by the facts.''
"Politics did not get into the redistricting suite,'' said Meros, who said that while Gaetz and Weatherford were "loyal'' Republicans they did not let that influence their decisions.
Meros acknowledged that a top aide to then-House Speaker Dean Cannon had shared information with a GOP consultant before it became public. He said that the aide, Kirk Pepper, made a "terrible mistake'' and had "breached the duty he owed to the speaker.'' Pepper now works at a lobbying firm started by Cannon.
But Meros said the defeat of U.S. Rep. Allen West in 2012 was proof enough that the final maps released were nonpartisan. After redistricting, West switched to another district and lost a narrow election to U.S. Rep. Patrick Murphy.
Meros also noted that U.S. Rep. John Mica was forced to run in a Republican primary against then-U.S. Rep. Sandy Adams and that U.S. Rep. Dan Webster had a close re-election contest.