NORTHBROOK, Ill. — Nancy Hirsch knows how to extract meaning from a pile of junk. At her northern Chicagoland recycling business, which she co-owns, construction waste arrives on trucks in mangled heaps of wooden beams, nails and concrete.

After being fed through a multimillion-dollar contraption that resembles a small roller coaster, the seemingly worthless rubble emerges at the other end of the building in tidy piles of raw materials that are loaded onto trucks and brought to market. And like C&D Recycling’s gruesome production process, Hirsch is blunt about what she wants nowadays from politicians.

“They need to cut payroll taxes,” she said. “Forget all of this other mumbo jumbo.”

In the coming months, Hirsch and other business owners and voters in this North Shore Congressional district will be busy sorting through the expected harsh rhetoric in the open-seat Congressional election to replace Rep. Mark Kirk (R), whose 2010 Senate aspirations offer House Democrats a rare pickup opportunity in an otherwise tough year for the majority party.

In a district carried by Democratic presidential nominees since Kirk was first elected in 2000, the moderate Republican’s politics struck an independent chord in the wealthy Chicago suburbs, whose Democratic-leaning electorate is one of the best-educated in the country.

For two consecutive elections, Kirk faced marketing consultant Dan Seals, a Democratic Congressional Campaign Committee-endorsed candidate. Seals emerged from nowhere in 2006 to finish within 7 points of Kirk, a surprise outcome for the then-unknown candidate. Still, with the DCCC’s backing in 2008, Seals did no better in a district that President Barack Obama carried with 61 percent of the vote.

The Democratic nominee has changed his tune dramatically now that he’s in his third attempt at winning the seat. He has abandoned his once-fierce criticism of the Iraq War and the Bush administration in favor of calls for fiscal responsibility and getting the economy back on track.

“The issue set is different,” Seals said of his current bid. “The economy is by far the No. 1 issue here.”

With Kirk now running for the Senate, Seals is once again making a play for the district’s large bloc of independent voters, traditional Kirk supporters who are estimated to be at least one-third of the electorate. Although Kirk’s politics have trended decidedly more conservative since he started running statewide, sources claim the incumbent’s House record was crafted to appeal primarily to this group, a heavily Jewish, pro-environment and abortion-rights-supporting set of voters who are not wed to a particular party. According to unscientific surveys cited by numerous consultants and campaigns, 20 percent of North Shore voters are Jewish.

“We know we have a lot of supporters” who are Kirk’s, Seals said. “They’re comfortable with the positions I’ve taken.”

Seals expects to raise $2 million for his 2010 race. Through the end of March, he raised $1.14 million, ending the quarter with $458,000 after a close primary with state Rep. Julie Hamos, who narrowly outraised him.

His GOP opponent this go-round, local businessman Robert Dold, raised about $921,000 through March 31, ending the first quarter with roughly $382,000 in cash, fundraising reports show.

Hamos has since endorsed Seals, telling a local newspaper after the primary, “At the end of the day, we’re all Democrats.”

In a recent interview, Seals suggested that his general election strategy will be to paint Dold as an extremist — an abortion rights opponent who is out of touch with the district’s independent voters. While Seals declined to directly criticize Dold, he offered a sneak peek at what his October advertising blitz might entail.

“The contrast between me and my opponent is larger and different” than in previous campaigns, Seals said.

A Democratic political consultant agreed with Seals that his best chance is to entice Kirk’s base into his corner — in the source’s words, “the Jewish community, the choice community and the environmental community.”

The source also said Seals will benefit from high name recognition after the millions of dollars that Kirk spent on television ads during his two most recent House contests.

“It never really was about Dan Seals the first two times around — it was about Mark Kirk,” the Democratic consultant said, adding that Seals has “an easier sell than two years ago.”

But a Seals victory is hardly a certainty, Republicans argue. Speaking to a reporter after a tour of Hirsch’s recycling facility, Dold said that he is also appealing to Kirk’s traditional swing base. He denied that he does not support abortion rights.

“I’m a pro-choice candidate,” Dold said.

Business issues and the economy are also the main plank of Dold’s 2010 campaign. He accused Seals of wanting to raise taxes — a charge that the Democrat denied — and hinted that Seals’ allegedly patchy employment history as a marketing consultant may again become political fodder. In a campaign memo last cycle, Kirk accused Seals of being a freeloader by living off his donors.

Seals says he’s now gainfully employed, but Dold — who owns a large pest control company — hinted in a recent interview that the issue may not be settled.

“He’s for increasing the size of the federal government,” Dold said. “I do own a business, I do employ people.”

A GOP consultant conceded that Dold is more conservative than Kirk. But with former Gov. Rod Blagojevich’s name in the news every day during his corruption trial, Republicans are hoping that a tarnished Democratic brand will help to make up the difference. And Kirk’s own recent admission that he misstated his military record could also become an issue.

“Being a little more conservative than Mark is not necessarily a bad thing,” the GOP source said.