LOMBARD, Ill. — The 6th Congressional District covers the western suburbs of Chicago. With its sprawling housing developments, warehouses, office complexes, light manufacturing plants and endless malls, it has become a national battleground to fill the open seat vacated by retiring Republican Rep. Henry Hyde. A Democratic victory could help break the Republican grip on Congress.

The Democratic primary will be held March 21. It pits three candidates against each other: Christine Cegelis, Tammy Duckworth and Lindy Scott. The winner will challenge right-wing state Sen. Peter Roskam in November’s general election.

The 6th CD has been a bastion of the Republican Party for years. But in 2004, Cegelis, running on a shoestring budget and without support of the national Democratic Party, garnered 44 percent of the vote against Hyde. John Kerry won 47 percent and Barack Obama won a majority in the district.

Support for Cegelis, an information technology professional, was fueled by her opposition to the Iraq war and President Bush’s other policies. She struck a chord among the changing population of the district, which includes growing working-class, Latino, Asian and African American communities. Grassroots anger was also stirred up by the Bush policies that caused job displacement from outsourcing and new technology, the bankruptcy of United Airlines, a major employer here, and the loss of other manufacturing, technical and management jobs.

The primary election has split the forces of the progressive movement. The Democratic establishment, including U.S. Sens. Dick Durbin and Barack Obama, and the Illinois AFL-CIO, SEIU and Illinois Citizen Action have endorsed Duckworth. The peace movement, many in the progressive community, some independent political organizations, Democracy for America, NOW, the Mexican American Political Coalition and the International Association of Machinists are supporting Cegelis.

While all three candidates oppose the Iraq war, Cegelis has taken the most advanced position, calling for an announced end to the occupation and a timetable for withdrawal of all troops. She opposed the war from the outset.

Duckworth, born in Thailand and raised in Hawaii, is an Iraq war vet, one of 12 veterans running for Congress as Democrats. She has called the war a mistake and supports the plan to withdraw troops based on building up Iraqi security forces.

Scott, a professor at Wheaton College, describes himself as a “progressive evangelical” whose campaign is largely self-financed. He has ties to the Latino community and supports a timetable for withdrawal from Iraq of 12-15 months.

Duckworth was severely injured in the war and lost both her legs. She was convinced to run by Durbin and Rep. Rahm Emanuel, who chairs the Democratic Campaign Committee, while she was rehabbing and fighting for services on behalf of other injured veterans.

The role of Emanuel angered many in the district who felt it was heavy-handed meddling and a clear slap at Cegelis’ independence. Emanuel’s move apparently reflected his fear that she was too progressive for area voters.

Cegelis, the granddaughter of a steelworker, has been building a grassroots apparatus in the district. She strongly opposed CAFTA and, in contrast to her opponents, said she would have voted against reauthorization of the Patriot Act. She supports HR 676, a single-payer health care bill introduced by Rep. John Conyers (D-Mich.), and is demanding more funding for education. In her last campaign, she supported the Steelworker’s Apollo job-creation and energy project.

Both Cegelis and Duckworth are strongly pro-choice, defend privacy rights of women and oppose requiring parental consent for teenagers seeking abortions.

Regardless of who wins, there is a strong sentiment among the candidates that everyone must unite in the general election. As Duckworth says, “We must keep our eye on the ball and defeat the Bush policies in November.”