In the 2000 election, no county in the country was more divided than Clay County, Mo. Here on the outskirts of Kansas City, in the northwest quadrant of the Show-Me State, a single vote separated Al Gore and George W. Bush: 39,084 to 39,083.

I wanted to see for myself what life was like in such a divided or, depending on your perspective, evenly balanced place, so I drove around the county for two days. Under the slate-gray sky was a portrait of America at the middle – factories and farms, city streets and small-town squares. Even the names of the towns – Liberty, Pleasant Valley – evoke a simpler America very different from New York City. A glance at the demographics reinforces this impression: a population of 184,000; 90% “white,” with a 70% home ownership rate and 50% living in the same house over the past 10 years, with a median income just below $50,000. They voted for the first President Bush, gave 27% to Ross Perot in 1992, and swung towards President Clinton in 1996. The front yards now alternate between Bush-Cheney and Kerry-Edwards signs.

I headed first to Liberty, where a block from the historic town square a 24-hour bail bondsman’s office stands across from a store devoted to Holistic Medicine. I sat down with Katee Porter, a young lawyer who heads up local Republican efforts, and asked what accounts for closely divided Clay County. “People here are not the most straight-party-line voters,” she said. “There are lot of moderate Republicans and a lot of moderate Democrats, to the point where the line gets really blurred.” But she’s confident that Republican ranks are growing, pointing to the influx of new residents and skyrocketing attendance at places like the 10,000-member Pleasant Valley Baptist church. Another indication of Republican strength is the September referendum banning gay marriage that gained 70% support amid record turnout. “I have heard from people that attended various churches that they were encouraged to get out and vote on that issue,” she confides. Mrs. Porter predicts a narrow Bush victory in Clay County this year, 51% to 49%, with Bush taking the state. But she does not know of any Gore voters from 2000 who are crossing party lines to vote for President Bush.

Her counterparts on the Clay County Democratic Committee are in agreement about the dynamics but not surprisingly differ on the outcome. The Democratic headquarters are in North Kansas City, near an intersection where a store called “Health and Home” sits next to “Denny’s Guns.” I met with Charles Myers, chairman of the Democratic Central Committee, and with a committee member, Sarah Jo Shettles, as a meeting got under way with the Pledge of Allegiance. They are presiding over what Mrs. Shettles calls “without a doubt the most organized ground game in my lifetime.” It began in January with voter-ID phone calls, and since July they claim to have registered 10,082 new voters. But spirits weren’t always so high at headquarters. “A month ago the morale of the people here was bad, until the first debate turned people around,” Mr. Meyers acknowledges. But the past weekend 375 volunteers showed up. “We have been getting people coming by everyday saying that they voted for Bush the last time, but they’re not voting for him this time,” he said.

Among these people is Jeanne Ralston, a lifelong Republican and self-described “William F. Buckley groupie in college.” She ran George H. W. Bush’s Clay County campaign in 1988 and was a member of the Republican Central Committee until this past fall. Now she is breaking with the president – with a vengeance. “I’m a Republican because I want less government in my life. Now they want to come into my house and tell me whether or not I can have an abortion. I call that government interference at the highest level,” she said. “But most of all I can’t conceive of supporting the war in Iraq, which makes no sense to me whatsoever.” She’s voting for Mr. Kerry without enthusiasm, while continuing to support local Republican candidates. “Some people say I’m leaving the party, but the party’s left me with this radical right-wing agenda,” she says. “The word Republican is now synonymous with conservative Christian.”

In search of perspective, I traveled to the bordering town of Independence, home of the Harry S. Truman Presidential Library and Museum. I sat down with the museum’s deputy director, Scott Rowley. “Missouri was a slave state,” he reminded me, “but so bitterly divided that it didn’t leave the union during the Civil War” – a swing state even then. Walking through the museum, I passed a video exhibit of politicians from both parties quoting President Truman and stopped at an electoral map from the 1948 election. It was almost a mirror image of the 2000 results, with Republicans capturing the solid northeast and Democrats winning much of the rest of the country. Truman won Missouri, as polls show President Bush likely to do next week. But the reversal of electoral allegiance was a stark reminder of the realignment we have seen in American politics over the past half century, a realignment that is still under way. On the ground in Clay County, a civil cultural war is driving the divisions in this election, and many moderate voters are finding themselves exiled on Main Street.