Republican members of the U.S. House of Representatives from Illinois are suing the state over new boundaries for congressional districts.

According to the lawsuit filed in federal court, the new map is an “outrageous partisan gerrymander” designed to eliminate five Republicans in next year’s election.

The lawsuit also makes the case that Latino voting power is being diluted. The map, it claims, packs “an excessive super-majority of Latino voters” into U.S. Rep. Luis Gutierrez’s district.

The complaint was filed by all of the state’s congressional Republicans except for U.S. Rep. Tim Johnson.

“While Congressman Johnson believes the redistricting process leading to this map was unfair and a distortion of the people’s wishes, these challenges have not succeeded in the past,” said Johnson’s spokesman, Phil Bloomer. “So Congressman Johnson has decided to devote his energy and his resources to his re-election campaign.”

Bloomer added that Johnson is “hopeful that an impartial court will modify the map in a way that’s in the voters’ best interests.”

If the map remains intact, it’s likely to set up some incumbent-versus-incumbent GOP primary fights. One Republican House member who finds himself in a complicated political position is freshman Joe Walsh from the Northwest suburbs. He currently represents the 8th Congressional District.

“I know I’m running somewhere,” Walsh said Tuesday, before the lawsuit was filed. “I don’t know where. I live in what would be the new 14th. My district office is in what would be the new 10th. A big chunk of my district is in what would be the new 6th.”

If Walsh does choose to run where he lives - the 14th - it is likely to set up a primary against another freshman congressman, Randy Hultgren.

On Wednesday, the heavy-weight conservative group Club for Growth announced in a news release that if the redistricting lawsuit fails, it will endorse Walsh for that seat.

“In less than a year, Congressman Walsh has distinguished himself as a pro-growth leader,” said Chris Chocola, the group’s president and a former congressman from Indiana.

Hultgren’s staff didn’t immediately return requests for comment.

Last week the GOP’s leaders in the Illinois legislature, state Rep. Tom Cross and state Sen. Christine Radogno, sued the state over the boundaries included in the map for state legislative districts.

Both lawsuits name as defendants the Illinois State Board of Elections, which will be represented in court by the office of Illinois Attorney General Lisa Madigan.

Regarding both cases, Madigan spokeswoman Robyn Ziegler emailed, “We plan to vigorously defend the state.”