The commission that drew the map followed a pattern traditionally seen in Colorado of separating areas with high Hispanic populations into separate districts, the filings argued. They said that though Latinos make up 21 percent of the state’s population, they are dispersed among several voting districts where they are outnumbered by white voters who tend not to elect their preferred candidates.

The rights groups requested that the map commission draw the district lines in a way that allows Latino voters to stay grouped together, the AP reported. They suggested that the city of Colorado Springs be split and its southern end, which has a high Latino population, be fused with a southern Colorado district that covers Pueblo and the San Luis Valley.

The commission, however, resisted the idea in the interest of preserving “communities of interest,” or areas with common needs.

For more reporting from the Associated Press, see below:

“The Commission treated Colorado’s substantial and growing Latino voter population as just another community of interest, no more important than those involved in ski recreation, living along a highway corridor, or working in the aviation industry,” LULAC argued in its filing, written by the Campaign Legal Center.

When it submitted the maps, the commission told the court they complied with the federal Voting Rights Act and did not discriminate against any voter on basis of ethnicity or language. The commission did not respond to the filings Friday.

Friday was the last day outside groups could challenge the maps that were submitted last week to the state’s high court. If the court finds the maps violate the state constitution it can direct the commission to re-draw them. It has until November 1 to make that decision.

This is the first redistricting cycle in which Colorado has used independent commissions—made up of 12 members evenly split among Democrats, Republicans and independents—to draw legislative lines—one for its eight congressional districts and one for its statehouse districts. The civil rights groups note that Latinos do not comprise a majority, or even a plurality, of any of the congressional districts.

Instead, they are often grouped with more conservative white rural voters, such as in the state’s new 8th district. That stretches from heavily-Latino Adams County, north of Denver, to Greeley and surrounding areas in Weld County. It’s a swing seat, but its partisan balance comes partly from grouping Democratic-leaning Latino communities with rural, more Republican white ones.

“This needless vote dilution is explained not by a desire to keep counties or communities whole but by an effort to increase competitiveness in one district,” the LULAC complaint said.