COLUMBUS, Ohio (CNN) -- Hillary Clinton drew the early support of much of Ohio's Democratic Party and most of its high-wattage politicians. And she was the overwhelming choice of the blue-collar workers who form much of the state's Democratic base.
Campaign volunteer Jeanine Michael has played a big role in Barack Obama's ground organization.
Barack Obama had his own staunch -- if slightly less high-profile -- Ohio loyalists: Valli Frausto and Jeanine Michael.
Now the Illinois senator has national momentum, and the resources to outspend Clinton on television advertising here by roughly 2-to-1. Still, as Tuesday's primary approaches and the battleground shifts from the airwaves to the the task of turning out the vote, the passion of a candidate's ground troops, not the size of the war chest, might be the most critical ingredient for success.
The party's apportionment formula means neither candidate is likely to gain much of an edge in the delegate count in Ohio without a massive, unlikely margin of victory.
But the vote in the general election is winner-take-all. And the primary might be the toughest test yet of Obama's ability to lay claim to a crucial swing state over a GOP turnout machine that delivered a second term in 2004.
"This state has been split down the middle," Michael said after an Obama appearance in Columbus, as volunteers waylaid attendees to press them to cast an early vote. Democrats may be posting gains in the state, but "If we're not at the top of our game on Election Day, that won't matter. We know we won't win." Watch Michael talk about her role in Obama's ground organization »
At the Service Employees International Union local, out-of-state arrivals who had paid their own way mingled with locals.
Web-recruited phone staffers and canvassers were armed with call lists and printouts of Obama's policy positions. Carefully plotted maps were distributed to groups headed out to visit voters door-to-door, and forms bearing fresh updates on all occupants of each home visited were collected from returning volunteers. Watch Obama's ground troops try to rally support »
The contents were entered into a database with the ability to sort that information precinct-by-precinct, block-by-block, house-by-house. Watch volunteers go door-to-door »
Downtown, the Obama office on East Rich Street -- in sight of Ohio Republican Party headquarters in Columbus -- was filled with a steady stream of volunteers, staffers and residents trading contact information for yard signs.
On a board just inside the front door, a list of office needs started with "HP ink cartridge #92 x3" and ended with "Obama to win." A sign that stretched across half the room read "Ohio the Closer."
In an overflow annex next door, Frausto said the grass-roots focus remained on Tuesday's primary. But, she added, everyone was aware of how the closeness of the contest be mimicked by a fight this fall against John McCain, the apparent Republican nominee.
"This is a test for us," she said, against a backdrop of disposable furniture, stacks of Obama literature and campaign volunteers.
In 2004, the powerhouse Ohio tag team of labor unions and well-funded independent groups like America Coming Together failed to outperform a disciplined, centralized Republican operation that retained a major technological edge.
If Obama wins, the task of taking on the seasoned GOP machine in this bellwether state will largely be in the hands of newly active campaign foot soldiers like Michael and Frausto.
Both say the Obama team's social-networking software, which helped draw them in, might be the weapon that finally brings parity to the turnout wars.
The new tool -- developed with the guidance of Facebook co-founder Chris Hughes, and under the leadership of Howard Dean Web veteran and Obama new media director Joe Rospars -- helped catapult the Illinois senator into contention across the country, even in likely Clinton firewall states like Ohio.
Frausto saw Obama for the first time last year on the "The Oprah Winfrey Show," went to hear him speak in Cincinnati and became one of the first in the state to create a user profile on the campaign's Web site last February. See a timeline of Obama's life »
She launched Obama-supporting groups that blossomed from a handful of members to dozens, then hundreds, as strangers connected online.
"I'm too old to be a Facebook person," said Michael, who was recruited by Frausto. "But then I thought: 'Hey, this is pretty cool.'"
Long before the campaign's Iowa field guru, Paul Tewes, or other full-time staffers arrived here, Frausto found herself at the forefront of a small army of unpaid workers, including Michael, who made telephone calls, canvassed and stumped for Obama in Ohio.
Last year, Obama volunteers staffed major Democratic events across the state, gathering and sorting voter contact information, recruiting volunteers and directing likely donors.
They occasionally crossed paths with an Edwards supporter -- "always the same one," Frausto said -- but in all that time, never ran into any of their counterparts on the Clinton campaign.
"It became clear over time that our group of grass-roots volunteers is a resource that Hillary doesn't have," said Frausto, a first-time campaign volunteer.
Frausto said the group assumed that the efforts were mostly symbolic because the party's presidential race was supposed to be over by Super Tuesday.
In 2004, the Democratic nominee was essentially decided by the time Ohio voted in March, and turnout was an anemic 14 percent.
But next week, both campaigns predict the fiercely contested primary may see turnout three times as high. Many of those voters will be Republicans and independents able to weigh in on the Democratic contest, thanks to the state's "semi-open" primary (registered voters can request either party's ballot at the polls.)
Obama's ability to draw these voters in numbers large enough to win a symbolically significant popular vote victory statewide will be seen by many as a signal of his team's effectiveness in what some volunteers are already calling a general election dry run.
If he does win the Democratic nomination, the job of making sure the senator holds onto his crossover support in November, calling those voters, cajoling them, running shuttles to and from the polls, will again fall to Frausto, Michael, and their counterparts. E-mail to a friend