Henry Kranz used to consider himself the Alex Keaton of his West Side Chicago family, the only Republican in a house full of Democrats. His first time at the ballot box, he voted for Republican Dick Ogilvie for governor. [Editor's note: The original version misspelled Kranz's name.]

Today, Mr. Kranz is more Toby Ziegler of "West Wing" than the Keaton character portrayed by Michael J. Fox. He and his wife joke about being "Swedish socialists" when they discuss issues like high CEO salaries. His top concern is healthcare, and he's a confirmed pacifist.

Still, Kranz - who used to run a small press and sponsor poetry readings, and now works with nonprofits to encourage charitable giving - doesn't think all the change has been his. Back when he voted for Ogilvie, it was because he valued the idea of "treading lightly on individual freedoms." It's a notion he still agrees with, but which he thinks the Republican Party has drifted from. He abhors proselytizing and has "real trouble with being my brother's keeper."

While there's no archetypal Illinois voter, Kranz's political journey is in some ways emblematic of the direction his state has gone. For decades, it was the classic swing state, voting for the winning presidential candidate 22 of 25 times in the 20th century. It went for Richard Nixon, Ronald Reagan, and Gerald Ford. From 1976 to 2002, Democratic mayors in Chicago were balanced by GOP governors in Springfield.

But lately, the state has grown steadily more Democratic and is no longer considered in contention in presidential politics. Voters went for Al Gore over George Bush by a surprising 12-point margin in 2000. Now, it's just one more US state that has left the middle ground, the Midwest's lone blue state in a Thomas Hart Benton landscape of purple and red.

A variety of factors is propelling the shift, everything from the Paul Simon effect - a reference to the popular late Democratic senator, elected by typically conservative downstate voters - to the lack of a Republican presence in Chicago, where just 1 out of 50 aldermen is from the GOP.

Suburbs and social issues

But perhaps most important, there's the steady trend leftward in the suburbs. Indeed, for much of the past century, Illinois was the prototypical swing state because of the ring of humanity around Chicago. While the Democrats dominated in urban Chicago and the Republicans downstate, the suburbs ended up playing referee. They still do, but with rising numbers of Democrats in what were once Republican strongholds.

"The mix has stayed pretty much the same in the city and downstate, but in the suburbs it's gone from being overwhelmingly Republican to being more competitive," says Dick Simpson, a political scientist at University of Illinois-Chicago and a former Chicago alderman.

The city, too, has been changing. Long a manufacturing hub, the City of Big Shoulders now has twice as many professionals and technicians as production workers. Instead of being a big brother to Kansas City or Detroit, Chicago now has a service-sector cosmopolitanism that makes it the heartland's biggest answer to coastal cities like San Francisco. Ruy Teixeira, coauthor of "The Emerging Democratic Majority," calls greater Chicago an "ideopolis" - a metropolitan hub with culture and diversity, where fewer people now pack meat and more practice law or perform in theaters. An economy oriented toward the production of ideas "tends to be fairly liberal, especially on social issues," he adds. Now "those kind of voters really set the tone in a lot of the suburbs."

Consider Monica Frigo, a young clerk who's lived in suburban Park Ridge for 19 years. She remembers when her family was the only one in her neighborhood with a Clinton/Gore sign out front. Now, Democrats "are starting to come out of the woodwork," she says, handing out Kerry/Edwards stickers at a town art fair. Plenty of residents are taking her stickers, including ones that say: "Republicans for Kerry."

Many inner-ring suburbs, within Cook County, have become Democratic. But even in farther reaches such as DuPage County, which has sent very conservative Congressman Henry Hyde to the US House since 1975, Democrats are starting to have a presence. Two Republican house seats in the suburbs, Mr. Hyde's and Phil Crane's, are considered in contention this fall.

In Cook County - where those inner-ring suburbs are concentrated - the trend is even more extreme. In 1996, the suburbs accounted for just 25 percent of the Cook County Democratic primary vote. By 2004, it was 37 percent. The upshot: Al Gore enjoyed a stunning 40 percentage point spread over George W. Bush in Cook County. Four decades earlier, in another tightly fought race, John F. Kennedy's margin over Richard Nixon there was 9 points.

Demographic change accounts for part of the shift, with newer arrivals including Hispanic immigrants, middle-class workers, and professionals from more liberal states. But many moderate Illinois voters have also become increasingly disenchanted with a Republican Party they see moving away from them on social issues. The result is an emerging Democratic bloc that is often fiscally conservative - antitax, for instance - but culturally more liberal.

"As the national Republican Party has moved farther to the right, especially on issues like choice and guns.... They have lost many mainstream Republicans who are turned off by that kind of position," says Michael Mezey, a political scientist at De Paul University in Chicago.

Luvie Myers is a case in point. She's the mother of three teenagers, the wife of a consultant, who's lived most of her life in Winnetka, an upscale suburb on Chicago's North Shore. Throughout the 1980s, Ms. Myers was a Republican, voting twice for Reagan and for the first President Bush. "He was a class act. Patrician, sensible, educated, very experienced in government - a lot like someone who would live in Winnetka," she says.

But she feels differently about Bush's son, and abhors the current Republican Party. The turning point for her was the rise of the culture wars. "In the 1980s, those conservative people who spent all their time telling you how to live your life were kind of on the fringe," she says. "Now you feel like the Republican platform has espoused these ideas that to me are institutionalized bigotry. I can't stand it."

How people feel about abortion and gay marriage has become a sort of litmus test, she says, and she has a harder and harder time relating to those people who come down on the opposite side of the debate.

The small-business Republican

Die-hard conservatives certainly remain in Illinois. But many Republicans here are people like Chuck Dressel, whose family has owned an hardware store since 1923. He's says he's Republican because "small business owners are Republicans." But he's antigun, for abortion rights and birth control, and would like to see healthcare extended to more people. He thought the invasion of Iraq "had to be done," but he's concerned about where the war is headed, and how many Americans have died. He's still leaning toward supporting Bush in November - he and his wife usually cancel each other out - but says his mind isn't made up.

"I guess I'm an economic Republican," he says, standing in an aisle packed with nails and bolts. "I'm not really excited about welfare for able-bodied people."

Mr. Dressel lives in River Forest, but neighboring Oak Park, where he runs his hardware store, has become one of the most liberal of the Chicago suburbs, a place that early on moved away from its Eisenhower roots and now exemplifies one of the new political truisms, that people seek out places where their neighbors think the same way they do.

A haven that's leafy, and liberal

A leafy oasis of top-notch schools and stately homes, but not far from the Loop, Oak Park has become a mecca for left-leaning professionals who want a suburban lifestyle but don't want what they consider the homogeneity or closed-mindedness of the suburbs.It's the birthplace of Ernest Hemingway and home to the largest concentration of Frank Lloyd Wright designs.

If Oak Park is more Democratic than most suburbs, the views of its residents reflect the broader shift that's been taking place in the surrounding area. Those residents are part of what pundits see as the growing base of the Democratic party: more white- than blue-collar, idealistic, highly educated professionals who listen to NPR and go to art-house films.

And they are active in politics. Signs for black Senate candidate Barack Obama began appearing on people's lawns six months before the primary.

Conversations with residents here reveal a rich tapestry of concerns, even if most agree on the man they'll vote for in November. For Kranz, healthcare is at the top of the list, because of how it has affected his own life. His wife, trained as a clinical psychologist, would like to have a private practice but instead designs employee-assistance programs for a company so the couple can get health benefits.

For Nancy Teclaw, an elderly woman who runs Oak Park's senior center and is a member of the local Rotary Club, the top issue is abortion rights. Ms. Teclaw always used to consider herself a Republican. Originally from northern Wisconsin, an area where being a Republican "was almost like a nationality," it was never really something she questioned. In 2000, she voted for Bush. But as an ardent supporter of abortion rights and, more recently, gay rights, she's slowly become disenchanted with the GOP.

Mary Wilkening and Dana Nasralla, two mothers out walking their kids around the neighborhood, have different reasons for their Democratic allegiance. Neither fits the liberal stereotype: They're evangelical Christians, heavily involved in church.

"Faith is kind of central to our family life," says Ms. Nasralla, carrying her 4-month-old baby Carter, named for the former president. "When it all comes down, it's: 'What would Jesus' answer to this be?' "

In politics, at least, these women have decided the answer to that question in a different way from many evangelicals. Ms. Wilkening ticks off the reasons she gives her 7-year-old son why she'll vote for Kerry. "I tell him, I'm unhappy with the war in Iraq, and I feel less secure in the world. I don't like Bush's economic policies, and I feel the world hates us. Then there's the environment, and the deficit."

Nasralla opposes abortion (an issue where Wilkening waffles: "I guess I'm more pro-life. But - keep your laws off my body"). It's the same with gay marriage, though living in such a diverse neighborhood seems to have softened their views.

On other issues, they have little doubt. Their husbands used to be Republicans, but both have "converted," they say. Nasralla's spouse, who is Arab, had a sign up for Bush in 2000, but now is disgusted with the president's Middle East policies.

Over at George's Family Restaurant and Pancake House, Arthur Murnan and Susan Perez are perhaps more stereotypical Oak Park residents. The friends were activists together back in the 1960s, marching together against the Vietnam War, and both remain politically active.

Ms. Perez is a devout Catholic, but she's not happy with the politics of her church, particularly the recent pronouncements by some bishops to deny communion to parishioners who support reproductive rights, or to those in Chicago who wore rainbow ribbons in favor of gay rights.

Both she and Mr. Murnan worry about the increased political divide in America, which they see within their own families. "It's much more extreme than when I started to vote," says Murnan. "When you look back to someone like Dwight Eisenhower - yeah, he ran on a Republican ticket, but he didn't seem like the Republicans today. The current president has made that dividing line real clear - you're either with us or you're against us."

Illinois not indelibly blue

If the choice this year seems clear-cut to many in suburban Chicago, Illinois still isn't a Massachusetts shade of blue. Its residents are mostly of solid Midwestern stock, not so firmly entrenched in the Democratic camp that they couldn't switch back if political winds changed. Indeed, the state's gubernatorial-vote history attests the readiness of many voters to support at least one brand of GOP leader.

"If at some point the Republican Party nationally is able to return to a more moderate brand of Republicanism," says Professor Mezey, "then Illinois could come back into play."

The state has its fair share of swing voters who jump across party lines based on a candidate's character or specific issues.

Mike Schroeder, a mild-mannered carpenter with a blond moustache, lives on the border between suburbs and farmland in Huntley, where most of his neighbors are Republican. Self-described as apolitical, he grew up in a Republican immigrant family in Chicago. Mr. Schroeder was excited about Al Gore in 2000.

"There was a guy that cared about the environment, was intelligent, was sensible," he says. But he also voted for Ronald Reagan twice. As Schroeder munches on toasted nuts at the Park Ridge art fair, he reveals his secret: "I just go with whoever seems to be the most sensible."

Next in Continental Divide series: The media and a split political landscape.