It’s the first Friday of April, and the tony main drag of this affluent exurb, thirty-five miles northeast of Philadelphia, is lined with people visiting the town’s cafes, galleries and bars. Doylestown is the political heart of Bucks County, one of the oldest and most hotly contested swing areas of the state. Three weeks before the state’s Democratic primary, Obama and Clinton supporters wave signs on every corner, and seemingly every other person sports a campaign sticker. “Seeing such outward Democratic activism in Doylestown is a little mind-blowing to me,” says Jordan Yeager, a local lawyer and Democratic Party organizer.

Doylestown, like much of Bucks County, used to be deeply, proudly, Republican. “In my youth, in central Bucks County, I grew up without knowing any Democrats,” James Michener wrote in Report of the County Chairman, his account of volunteering for John F. Kennedy in 1960. “My mother thought there might be some on the edge of town, but she preferred not to speak of them.” Things began to change in 1992, when the recession that year pushed Bucks County toward Bill Clinton. In the following years, as the GOP increasingly became identified with the religious right, the county voted for Democrats for President. Yet until recently, Republicans controlled all the levers of local government. “When I moved here five years ago, I was told to register as a Republican because that’s the way business is done around here,” says Allen McQuarie, an Obama volunteer who came from the nearby town of Holland.

A surge of Democratic activism in the past few years has turned Doylestown, and much of the county, from red to purple–and quite possibly to blue. In 2003 Republicans dominated the borough council 9-0; now it’s 6-3 Democratic. After sending Republicans to Congress in every election since 1993, in 2006 Bucks County’s 8th Congressional District elected Democrat Patrick Murphy, a 34-year-old Iraq War vet. In January there were 21,000 more registered Republicans than Democrats in Bucks. By early April, thanks to a massive voter-registration drive, Democrats outnumbered Republicans for the first time since 1978, when Democrats briefly held sway after Watergate. “The Bush presidency has tarnished the Republican brand and provided an opening to listen to the other side,” says Neil Samuels, deputy chair of the Bucks County Democratic Party.

What’s happening in Bucks mirrors trends throughout Pennsylvania, where the state Democratic Party has added a remarkable 300,000 voters since January. Nearly half of these Democrats, according to the state board of elections, are new or previously unregistered voters lured by the excitement of the Clinton-Obama race. The other half are former Republicans and independents who switched to vote in the Democratic primary, mostly for Obama. Before the March 24 registration deadline (only registered Democrats may vote in the April 22 primary), the Obama campaign made an all-out effort to convert disaffected Republicans, otherwise known as “Obamicans.”

In Bucks County there are “regular Obamicans”–former Republicans who volunteer only occasionally for Obama, if at all–and “super-volunteer Obamicans,” Yeager tells me, half-jokingly. Christine Harrison, a peppy former travel agent who dates her ancestry back to President Benjamin Harrison, is a super-volunteer Obamican. Raised in a family of lifelong Republicans, Harrison has never in her life voted for a Democrat. But after watching the Democratic debates and Obama’s victory speech in Iowa, she caught the Obama bug. Harrison attended the opening of his office in Doylestown, the Friday before Super Tuesday, and met Peachy Myers, an energetic veteran of Obama’s South Carolina field team, who asked her to volunteer. “I told her I’m a Republican and she said, That’s OK,” Harrison recalls. “So I said, Well, let me be your very first Obamican! And I changed my registration right there.” Harrison’s now a volunteer coordinator for Obama, spending all her waking hours helping to get a Democrat elected President. Ten members of Harrison’s all-Republican family have since changed their affiliation–all for Obama.

Victor Unger, an 80-year-old retired research director for a chemical company, is more of a regular Obamican. Unger has been a Republican since he moved to Bucks County in 1968. Almost two years ago Unger and his wife, a Democrat, heard Obama speak about his book The Audacity of Hope. Unger read both of Obama’s books and “was really impressed by his intellect.” “He’s running at the right time in our history,” he says. Unger changed his registration in March and began occasionally stopping by the Obama office to help out where needed.

It seems like every prominent Democrat in Bucks used to be a Republican–or is married to one. Congressman Patrick Murphy’s wife, Jennifer, a 33-year-old lawyer, is another lifelong Republican. “Every time I went to the polls I saw a Clinton or a Bush on the ballot, and I voted for a Bush or against Clinton every time,” Murphy says. Her husband was the first Democrat Murphy ever voted for, and Obama will be the second.

Like many Republicans in Bucks County, Murphy describes herself as fiscally conservative and socially moderate. “I still, for the most part, consider myself a Republican,” she says, and inverts Ronald Reagan’s famous maxim: “I didn’t leave the Republican Party, the Republican Party and this President left me.” Disaffected Republicans in Bucks, furious at how George W. Bush and the religious right hijacked their grand old party, are voting Democratic in the primary out of frustration, not because Rush Limbaugh told them to. The quagmire in Iraq and the downturn in the economy matter to these voters, but so do issues of personal freedom, like reproductive rights, technological advances like stem-cell research and protecting the environment–all neglected or opposed by the current GOP.

Bucks County, though almost entirely white, is still a good microcosm of Pennsylvania as a whole, which in turn looks like much of America. There’s blue-collar, heavily Democratic Lower Bucks County, near Philadelphia; the more affluent and politically mixed areas in the middle like Doylestown; and Upper Bucks County, which is predominantly rural and Republican. After visiting Doylestown I stopped by the newly opened Obama campaign office in Quakertown, nestled in the rolling hills and farmland of Upper Bucks. Voters here tend to be more conservative, fiscally and socially, than the rest of the county. Yet on a brisk Sunday afternoon, a steady stream of Republican switchers walked through the doors of the Obama office. Each one pointed to a specific conversion moment. For Barbara Baker, a registered nurse, it was Obama’s electrifying speech at the Democratic convention in 2004. For Carl Soderberg, an office supervisor at a mail-order company, it was the “excitement in the air after Iowa.” For Jane Shafer, a retired Montessori school teacher, it was Obama’s “eloquence” and stance on education. For Maryeileen Wojt, a registered nurse, and her husband, a financial trader, it was the threat of a looming economic recession. Wojt is antichoice, supports restrictions on stem-cell research and still has a Bush/Cheney sign in her basement. “Our country is in such a desperate state,” Wojt said, “that we saw Obama as the only hope and possibility.”

Many of these Obamicans are voting as much against the Clintons as for Obama. “I hate the Clintons,” Harrison told me point-blank. “I find Bill fairly reprehensible,” Unger said, “and have overwhelmingly negative feelings toward Hillary.” “I don’t trust her. She’s not ethical,” Wojt said. Many Obamicans, these included, said they’d vote for John McCain in the general election if Clinton was the Democratic nominee, or wouldn’t vote at all. Harrison said all ten members of her family would switch back to the GOP. (Of course, Clinton supporters sometimes say the same thing about Obama, although support for her is more likely to come from core Democratic constituencies. I asked the Clinton campaign to provide me with a list of switchers to interview in Bucks County. It didn’t.)

Obama’s Republican supporters see in him what Bush promised to be in 2000: a great uniter. “He doesn’t see me as a sworn mortal enemy because I’m a Republican,” Jennifer Murphy says. Clinton and Obama may be virtually indistinguishable liberals on most policy positions, but Obamicans see their man as a kindred spirit, someone who will–as his campaign often reminds us–bring people together and bridge the partisan divide.

Before the ’06 elections, I interviewed a bunch of former Republicans in Bucks County who were voting Democratic primarily because of the war in Iraq and the scandals of the Republican Congress. What’s striking–and a little disturbing–about the Obamican phenomenon in ’08 is how much it rests not so much on specific issues but on the candidate’s personal characteristics and calls to transcend race and achieve political unity. Will these same voters still support him when Obama tries to withdraw from Iraq, or pass universal healthcare, or raise taxes on the rich, or push for any number of policy programs that are likely to anger many core Republicans? The Obamicans could turn out to be just another passing political fad. After all, conservative columnists like David Brooks and George Will heaped praise on Obama early in the campaign season, only to turn against him later. In a general election, McCain–with his maverick reputation, however dated or inaccurate–could stop the bleeding in places like Bucks County, keeping the remaining moderate Republicans in the GOP fold.

Obama is expected to do well in Philadelphia and its suburbs, but he faces an uphill climb in the rest of the state. Yet if he can go on to win the nomination and keep his Republican converts in the Democratic column come November, and beyond, he may achieve what no President since Reagan has–an enduring realignment of crossover voters.